In 1994 and 1995, the Japanese cult Aum Shinrikyo used homemade VX to attack three people, one of whom died.

North Korea is estimated to have a chemical weapons production capability of up to 4,500 metric tons during a typical year and 12,000 tons during a period of extended crisis. It is widely reported to possess a large arsenal of chemical weapons, including mustard, phosgene and sarin gas, a United States Congressional Research Service report said last year.

The announcement by Malaysia’s police chief came just a day after North Korea denied any responsibility for Mr. Kim’s death, accusing the Malaysian authorities of fabricating evidence of Pyongyang’s involvement under the influence of South Korea.

With the North’s reclusive government on the defensive about the Feb. 13 killing of Mr. Kim, the estranged half brother of Kim Jong-un, at the airport for the Malaysian capital, Kuala Lumpur, a statement attributed to the North Korean Jurists Committee said the greatest share of responsibility for the death “rests with the government of Malaysia” because Kim Jong-nam died there. And in what could be seen as a threat to Malaysia, the statement noted that North Korea is a “nuclear weapons state.”

But in a case that has been filled with mysteries and odd plot twists, North Korea still would not acknowledge that the man killed was indeed Kim Jong-nam. And it gave no indication that it would agree to Malaysia’s demands to question a senior staff member at the North Korean Embassy in Kuala Lumpur in the investigation into Mr. Kim’s death.

Relatives and acquaintances of the two women Malaysia has accused of carrying out the killing, by applying poison to Kim-Jong-nam’s face as North Korean agents looked on, insisted they must have been duped into doing so, though the Malaysian authorities say otherwise.

“I don’t believe Huong did such a thing,” said Doan Van Thanh, father of Doan Thi Huong, 28, a Vietnamese woman being held in Malaysia. “She was a very timid girl. When she saw a rat or frog, she would scream.”</s>Malaysian police are investigating how the highly toxic nerve agent VX, identified as the chemical used in the murder of Kim Jong-nam, the estranged half brother of North Korean Supreme Leader Kim Jong-un got into the country.

Police chief Inspector-General of Police Khalid Abu Bakar told reporters: "We don't know yet [about the origins of the chemical]. We are trying to find out."

"But if it is a very small amount, it would have been very hard to detect," he added, according to The Star.

Reuters reported that police are investigating whether the chemical, believed to be the most toxic nerve agent in the world, was brought into Malaysia or made in the country itself.

Jong-nam died after being poisoned by the chemical at the Kuala Lumpur International Airport 2 on 13 February.

According to the US Army's Edgewood Chemical Biological Center, the chemical is fatal after only 15 minutes if absorbed in large doses.

The news agency said that in 2015, traces of sarin and the VX nerve agent were found at a military research site in Syria, that had not been declared to the global chemical weapons watchdog.

Separately, Khalid told reporters that one of the two women held in custody over the killing of Jong-nam also suffered the effects of the VX nerve agent.

"She was vomiting," he said, in reference to the symptoms the woman suffered from.

He declined to elaborate, Reuters reported. The police chief also did not identify which of the two female suspects was affected.

Malaysian police nabbed four people — Indonesian woman Siti Aisyah, a Vietnamese woman Doan Thi Huong and two other men, a Malaysian and North Korean — over the murder of Jong-nam.

They have on Thursday (23 February) requested Interpol to put an alert out for additional North Korean suspects who they believe have fled the country on the day of the attack.

The ppolice are also seeking to question the second secretary at the North Korean embassy in Kuala Lumpur and two others North Koreans, including an employee of the state-owned airline Air Koryo.</s>Malaysian police said the highly toxic chemical – classified as a weapon of mass destruction by the UN – was found at the crime scene after Kim Jong-nam was killed. Kim, 45, was the oldest son of Kim Jong-ill, the current leader's father and predeccesor.

Initial reports by South Korean media say he was killed at Kuala Lumpur airport by two women, said to be North Korean operatives, carrying a "poisoned needle". The substance believed to be used in the killing is extremely potent, with just 10 milligrams being a lethal dose.

Kim-Jong-nam had spent the best part of a decade in exile, having fallen out of favour with his late father. He was born out of wedlock to Kim-Jong-il and his mistress, the actress and Song Hye-rim.

He had been favourite to replace Kim Jong-il until he was arrested at a Tokyo airport in 2001 with a forged passport trying to get to Disneyland. The incident caused great embarrassment to the leader, and Nam was exiled to China, where he lived in Macau on the south coast.

When his younger sibling Kim Jong-un became leader in 2011, Kim Jong-nam went into hiding, fearing his half-brother would see him as a threat to his regime and have him eliminated. And Malaysian police reported this week the two women arrested in connection with the killing may have been trained in assassination.</s>VX nerve agent used in murder of Kim Jong-nam, Malaysia says

A preliminary report shows the murder of Kim Jong-nam was carried out with a highly toxic chemical known as VX nerve agent, Malaysian police say.

The police said swabs were taken from the eye and the face of a North Korean national by the Chemistry Department of Malaysia.

A statement from the inspector general of police said a preliminary analysis from the department identified the substance as VX nerve agent, or S-2 Diisoprophylaminoethyl methylphosphonothiolate, a chemical classified as a weapon of mass destruction by the United Nations.

"Other exhibits are under analysis," Malaysian police chief Khalid Abu Bakar said in the statement.

Mr Khalid said earlier that a Vietnamese woman and an Indonesian woman wiped a liquid on Kim's face.

They later washed their hands and fled the scene.

Airport camera footage released on Monday by Japanese broadcaster Fuji TV shows the moment the women appeared to assault Kim, who is later seen asking airport officials for medical help. He died on the way to hospital.

VX is tasteless and odourless, and is outlawed under the Chemical Weapons Convention, except for "research, medical or pharmaceutical purposes".

It can be manufactured as a liquid, cream or aerosol. Absorbed in large doses, it is fatal after 15 minutes, according to the US Army's Edgewood Chemical Biological Centre, making it the most toxic known nerve agent in the world.

Kim, the estranged half-brother of North Korean leader Kim Jong-un, died on February 13 after two women put a substance on his face while he was checking in at Kuala Lumpur International Airport while he was preparing to board a flight to Macau.

Police chief Khalid said help had been sought from Interpol to issue an alert for the four North Korean suspects who left Malaysia on the same day Kim was killed.

It was unclear what Interpol could do, as the four are believed to have returned to Pyongyang and North Korea is not a member of Interpol.

Mr Khalid said there were no plans to send officers to Macau to collect a DNA sample from Kim's family.

Kim had a home in Macau and was on his way there when he was killed.

North Korea said Malaysia's investigation into the death of one of its nationals was full of "holes and contradictions" amid speculation its agents masterminded the assassination.

Malaysian police have not directly pinpointed North Korea as being behind the death of Kim.

The Korean Jurists Committee said in a statement on state-run news agency KCNA that the Malaysian investigation lacked fairness and has been influenced by the South Korean government, which blames Pyongyang for the death.

The North has not acknowledged that the dead man is Kim.

Thursday's statement described the man only as a North Korean citizen bearing a diplomatic passport.</s>On Friday morning, Malaysian police confirmed that Kim Jong-un’s half-brother, Kim Jong-nam, was assassinated with the VX nerve agent at Kuala Lumpur International Airport. North Korea is thought to possess the world’s third largest chemical weapons stockpile after the United States and Russia, with one estimate noting that it may possess 2,500 to 5,000 tons of chemical warfare agents. To date, while VX had thought to be an objective for North Korea’s chemical weapons program, there had been no evidence that Pyongyang possessed the highly dangerous nerve agent.

Kim Jong-nam’s assassination, which took place on February 13, has been surrounded by intrigue and speculation, ranging from the extent to which the North Korean mission in Kuala Lumpur provided direct support to the motivations of the two female assassins involved. Malaysian authorities have held individuals at the North Korean embassy in the country liable for involvement in the attack and the use of VX adds to the growing list of evidence pointing to the fact that this was a state-sanctioned assassination, despite ongoing North Korean denials.

North Korea’s use of VX is especially audacious given that it occurred at a busy international airport. VX is so dangerous that the median lethal dose is estimated at 10 mg. The United States Centers for Disease Control and Prevention notes that “people can be exposed through skin contact, eye contact, or inhalation.” The agent can kill within minutes of making contact with human skin. In Kim Jong-nam’s case, Malaysian authorities noted that the agent was detected in his eyes; chemical nerve agents generally work faster once they’ve made contact with mucous membranes such as those found in the human eye.

Remarkably, no reports have emerged to date of any individuals suffering from the VX use at Kuala Lumpur International Airport on February 13. Both assassins survived to end up in Malaysian custody and Malaysia has not specifically announced if any medical or airport staff who handled Kim Jong-nam’s body fell ill or demonstrated any signs of having come into contact with a deadly nerve agent.

Indeed, one of the remaining mysteries in this case now, with the confirmation of VX use, is how neither of the assassins nor any bystanders appear to have been affected. One possibility — suggested by the use of multiple assassins instead of one — is that a VX binary was used, but this has not been confirmed by Malaysian authorities. In a two-stage binary VX reaction, two otherwise safe precursor compounds synthesize the dangerous nerve agent. Accounts of the Kim Jong-nam assassination — including CCTV footage — have confirmed at least two women approached Kim, one of whom put him in a two-handed chokehold. (The U.S. Army first developed binary nerve agents to enable safer handling and storage.)

North Korea is not party to the Chemical Weapons Convention, but has signed the Geneva Protocol restricting the use of chemical agents in war. According to the Nuclear Threat Initiative, “at maximum capacity, North Korea is estimated to be capable of producing up to 12,000 tons of CW.” For wartime use, South Korea seemingly expects delivery of chemical or biological agents by conventional artillery shells. In 2010, after the shelling of Yeonpyeong Island, fearing chemical use in the future, South Korea handed out gas masks to the island’s residents.

It’s unclear if the Kim Jong-nam assassination was meant to serve the secondary purpose of signaling to the world that North Korea definitively possesses the capability to synthesize VX. Immediately after Kim Jong-nam’s death, North Korea protested Malaysia’s intention to proceed with an autopsy and demanded that the body be transferred to its diplomatic mission. Melissa Hanham, an arms control expert at the James Martin Center for Nonproliferation Studies, told The Diplomat that North Korea’s denials in the press and suspected attempt to even break into the morgue where Kim Jong-nam’s body also add confusion to the situation.

The choice of VX for the assassination, however, isn’t unprecedented. Japanese doomsday cult Aum Shinrikyo used the nerve agent for the 1995 assassination of Tadahito Hamaguchi in Osaka, with VX emerging in the autopsy. Aum Shinrikyo also carried out an attack on the Tokyo subway with sarin, another nerve agent, in 1995, killing 12 and injuring more than 4,000. North Korea has used poison-laced needle attacks in assassination attempts in the past; South Korean authorities reported three such incidents against South Korean activists helping North Korea defectors as recently as 2011.

For the moment, the Malaysian investigation into the Kim Jong-nam assassination continues, but the confirmation of VX use by North Korea, while troubling, only raises more questions.

Update: Malaysian authorities have confirmed to Reuters that one of the assassins showed effects of VX exposure, including vomiting.</s>A highly toxic chemical was used in the death of North Korean leader Kim Jong-un's half brother last week, tests have shown.

Swabs taken from his face revealed that Kim Jong-nam had been sprayed with VX nerve agent - classified by the United Nations as a weapon of mass destruction.

Malaysian police announced on Friday that tests on the eyes and face of a North Korean national had been conducted.

Kim, 45, died shortly after appearing to be attacked by two women at Kuala Lumpur airport while he was waiting to board a flight to Macau.

The substance reported to have been found on his person is also known as S-2 Diisoprophylaminoethyl methylphosphonothiolate.</s>In the seedy, sex-driven, underworld beneath Malaysia's world-wide image of respectability, two 'good time girls' made easy pickings for North Korean agents looking for 'patsies' to commit a murder.

Today the women, Doan Thi Huong, from Vietnam, and Siti Aishah, from Indonesia - both in their mid to late 20s - continued to be interrogated by Malaysian police about their roles in the murder of Kim Jong-nam.

They are understood to have admitted they had worked in massage parlours and had also escorted wealthy Asian men around town, ending up in their bedrooms - and they made easy pickings for North Korean agents looking for women who could assume harmless identities for the deadly roles they were needed for.

Police are understood to be looking at preparing murder charges against the women despite their agreeing to tell everything about the men they met, the names they knew, and the promises that were made to them if they carried off their deadly mission of murdering Kim, the estranged elder half-brother of North Korean leader Kim Jong-un.

Aishah has already admitted that she worked in a massage parlour, while Huong has told police that she earned money for her family back in Vietnam by escorting men in night clubs and being paid well for her services.

But, aside from the serious charges they now face - despite their claims that they thought they had been recruited to play a part in a jokey TV show in which members of the public would have a liquid sprayed in their faces - Huong has an added reason to regret.

She has fallen sick, police revealed, because she ingested some of the 'harmless' liquid she and Aishah were involved in spraying in Kim's face at Kuala Lumpur airport.

She has been vomiting and refusing food, sources said, because the liquid has been identified as a deadly nerve agent known as VX. Although she is not in any danger to her life, it is possible that she did not wash her hands properly after the airport incident.

Just where the deadly chemical came from - whether it was brought into the country by a North Korean agent or was produced locally - was still being investigated today but suspicion that it might have been produced in Kuala Lumpur has been suggested by The Star newspaper.

It reported that a hazardous material team had gone to an apartment in the city, understood to be where North Korean chemist, Ri Jong-chol, had been living, and had seized various chemicals, several pairs of gloves and shoes.

Malaysian experts are now trying to ascertain whether the deadly chemical used to kill Kim was made up of more than the nerve agent VX. But as far as the two arrested women were concerned, they continue to claim they did not know its dangers.

Aishah has told police that she believed the liquid was just baby oil.

Indonesia's deputy ambassador to Malaysia, Andreano Erwin, told reporters today that Aishah had been paid the equivalent of £72 to take part in the 'prank'.

'She didn't know it was poison. That is the answer from her,' he said.

'She only said in general that somebody had asked her to do it and she didn't know what would happened next.

'She mentioned some names but I did not recognise them. The names were very general…James, Jang, that's it.'

He said Aishah had told him that the men who had approached her were 'maybe Japanese or Korean.'

Eight North Koreans are wanted in connection with the murder, four of whom are suspected of having already escaped back to Pyongyang, but police are hoping for a 'big catch' with the arrest of a diplomat at the North Korean Embassy.

They have ordered 44-year-old Hyon Kwang Son, a second secretary at the embassy, to co-operate voluntarily with police - and he has been given 'reasonable time' to come forward.

Police chief Abdul Samah Mat said that if he failed to co-operate a warrant would be issued for his arrest.

Malaysian police Saturday told the public they would do everything possible to ensure there was no risk from the lethal VX nerve agent used to assassinate Kim Jong-Nam, the half-brother of North Korean dictator Kim Jong-un.

People were worried about the use of the highly toxic agent developed for chemical warfare, state police chief Abdul Samah Mat said, after the audacious February 13 attack by two assassins at Kuala Lumpur airport.

HOW A SINGLE DROP OF MAN-MADE VX KILLS IN MINUTES As Malaysian toxicologists reveal that the banned nerve agent VX was used in the airport assassination of Kim Jong-Nam, here are some key questions and answers about the deadly weapon of mass destruction. Code-named by the US scientists who mass produced it, VX is an organophosphate compound and one of the deadliest chemical agents ever manufactured. Stockpiled by the US in huge quantities during the Cold War, VX is perhaps 10 times as powerful as the Sarin toxin. Odourless and clear when pure, it has the appearance of motor oil and is stable enough to be transported. It is also hard to detect, an advantage for a would-be assassin. Downsides are that it lingers, potentially contaminating areas for long periods of time. 'It can kill an adult weighing 70 kilogrammes with just five milligrammes on the skin,' said Yosuke Yamasato, former principal of the Japan Ground Self-Defense Force Chemical School. 'It's unbelievable that the executors of the crime used it with their bare hands - they must have not known the material was VX.' Code-named by the US scientists who mass produced it, VX is an organophosphate compound and one of the deadliest chemical agents ever manufactured (file picture) It strikes the nervous system fast. A high dose can kill in minutes when inhaled, as the blood vessels in the lungs rapidly spread the compound into the bloodstream and vital organs. Nerve agents over-stimulate glands and muscles, leading them to quickly fatigue and become unable to sustain breathing. Symptoms depend on dosage and whether it is inhaled or introduced through the skin - the slower form of poisoning. But more serious contamination is fast-acting and often gruesome. People exposed to the toxin may become short of breath and nauseous in minutes, or at a higher dose experience seizures, heart failure and a total shut down of the respiratory system. There are antidotes but treatment must be immediate. US soldiers carried kits to inject themselves with antidote during the first Iraq War. Nerve agent VX is odorless, tasteless and highly toxic, and is manufactured for chemical warfare The compound was first created in a British laboratory in the early 1950s. But American scientists honed its potency during the Cold War arms race with the Soviet Union. Tens of thousands of tonnes of VX were churned out at Newport Chemical Depot in Indiana - a stockpile that was finally destroyed in the late 1980s as the Cold War ended. Accidental leaks have been reported in the US and Japan. It has been deployed as a war weapon infrequently but with devastating effect. Residues found on site suggest Iraqi dictator Saddam Hussein may have used VX among a cocktail of chemical weapons he rained down on the Kurdish town of Halabja in 1988 killing at least 5,000 people. In 1994 VX was used by Japan's Aum cult to murder an office worker in Osaka, and in the attempted murder of two other people. VX is listed a weapon of mass destruction by the United Nations. Under the international Chemical Weapons Convention 1997, countries are allowed limited stockpiles for research purposes only but must declare them and are obliged to progressively destroy their supplies. 'North Korea is not a signatory to CWC, so it's no surprise if it possesses VX,' Satoshi Numazawa, professor of toxicology at Showa University, told AFP.</s>Kim Jong Nam, the estranged half brother of North Korean leader Kim Jong Un, had been exposed to nerve agent, police in Malaysia said Thursday.

According to the police, a preliminary analysis found VX nerve agent on the face of the victim, who was killed on Feb. 13.

The Centers for Disease Control says VX "is a human-made chemical warfare agent classified as a nerve agent."

"Nerve agents are the most toxic and rapidly acting of the known chemical warfare agents," the site adds.

According to The Associated Press, two women suspected of poisoning Kim Jong Nam were trained to deliver toxic substances by putting them on their hands and wiping them on his face.

"We strongly believe it is a planned thing and that they have been trained to do that. This is not just like shooting a movie," said Inspector-General of Police Khalid Abu Bakar, according to the AP.

As of Tuesday, four people had been arrested, including the two women. At least one claimed she was tricked into participating in the attack, the AP said.</s>The chemical substance used to kill Kim Jong Nam was VX nerve agent, according to a preliminary report by the Chemistry Department of Malaysia, Malaysian police said in a statement Friday.

Nerve agents are the most toxic and fast-acting substance known in chemical warfare — and VX is the most potent of all of them, according to the US Centers for Disease Control and Prevention.

Kim, the half-brother of North Korean leader Kim Jong Un, died February 13 before he was scheduled to board a flight from Kuala Lumpur to Malaysia.

The Royal Malaysian Police say that two women approached him from behind and wiped his face with some sort of substance.

They were instructed by four North Koreans, who are believed to have returned to Pyongyang, Malaysian Inspector-General of Police Khalid Abu Bakar said at a news conference Wednesday.

VX works by inhibiting the operation of an enzyme that helps the body’s nervous system function, according to the Organization for the Prohibition of Chemical Weapons.

It’s more dangerous when exposed to skin in comparison to Sarin, another nerve agent. Nerve agents on the whole work faster when they are absorbed through the respiratory system.

Symptoms can appear after a few seconds, and even small doses can affect people. Larger exposure can lead to convulsions, paralysis and deadly respiratory failure.</s>The estranged half-brother of North Korean leader Kim Jong Un was killed with a highly toxic chemical weapon known as VX nerve agent, Malaysian police said Friday, citing a preliminary report.

Kim Jong Nam died after being assaulted at Kuala Lumpur International Airport last Monday while preparing to board a flight to Macau.

South Korean and U.S. officials have said they believe North Korean agents assassinated Kim Jong Nam, who had been living in the Chinese territory of Macau under Beijing’s protection.

Police said swabs taken from the eye and the face of a North Korean national by the chemistry department of Malaysia revealed the presence of VX.

VX nerve agent, or S-2 Diisoprophylaminoethyl methylphosphonothiolate, is chemical weapon classified as a weapon of mass destruction by the United Nations.

“Other exhibits are under analysis,” Malaysian police chief Khalid Abu Bakar said in the statement.

Police chief Khalid said earlier that a Vietnamese woman and a Indonesian woman wiped a liquid on Kim Jong Nam’s face. They later washed their hands and fled the scene.

Airport camera footage released Monday by Japanese broadcaster Fuji TV shows the moment the women appeared to assault Kim Jong Nam, who is later seen asking airport officials for medical help. He died on the way to hospital.

VX is tasteless and odorless, and is outlawed under the Chemical Weapons Convention, except for “research, medical or pharmaceutical purposes.”

It can be manufactured as a liquid, cream or aerosol.

Absorbed in large doses, it is fatal after 15 minutes, according to the U.S. Army’s Edgewood Chemical Biological Center, making it the most toxic known nerve agent in the world.

Malaysia on Thursday requested Interpol to put an alert out to apprehend four North Korean suspects in the murder.

Police are also holding one North Korean man, but are seeking another seven in connection with the murder.
Malaysian police claim that Kim Jong-nam, half brother of North Korean leader Kim Jong-un, was killed by VX nerve agent, a toxin used almost exclusively for chemical warfare.