— Reuters picLONDON, April 4 — The British military facility analysing the nerve agent used to poison a spy said yesterday it could not prove the substance was made in Russia, as Russian President Vladimir Putin put his hopes in a meeting with the world’s chemical weapons watchdog. The revelations of top British military scientists have thrown the social media into an uproar as it became apparent that new statements cast doubt on earlier claims made by Foreign Secretary Boris Johnson regarding the alleged nerve gas attack in Salisbury.Gary Aitkenhead, chief executive of the Defesce Science and Technology Laboratory at Porton Down in England, told Sky News that while the scientists managed to identify the chemical used in the Skripal poisoning case as a "military-grade nerve agent," they were unable to determine its "precise source. But he added: “We have not identified the precise source.”

“It is our job to provide the scientific evidence of what this particular nerve agent is, we identified that it is from this particular family and that it is a military grade, but it is not our job to say where it was manufactured,” Aitkenhead said. We have removed this tweet.”

READ MORE: Salisbury poisoning: Porton Down can’t verify nerve agent is Russian

In an interview on German TV on 20 March when he was asked why the UK believed that Russia was the source of the nerve agent, Mr Johnson said: “The people from Porton Down, the laboratory, they were absolutely categorical. As the Prime Minister has set out in a number of statements to the Commons since March 12, this includes our knowledge that within the last decade, Russia has investigated ways of delivering nerve agents probably for assassination - and as part of this programme has produced and stockpiled small quantities of Novichoks; Russia's record of conducting state-sponsored assassinations; and our assessment that Russia views former intelligence officers as targets. Russia's Ambassador to the UK, Alexander Yakovenko, says that London's reluctance to share information on the March 4 poisoning of the former double agent and his daughter has led Moscow to suggest that London authorities actually perpetrated the crime.
Military scientists at Porton Down state they are uncertain of the source of the nerve agent used, but are "completely confident" it was a Novichok agent.