Images and accounts of the North Korean gulag become sharper, more harrowing and more accessible with each passing year. A distillation of testimony from survivors and former guards, newly published by the Korean Bar Association, details the daily lives of 200,000 political prisoners estimated to be in the camps: Eating a diet of mostly corn and salt, they lose their teeth, their gums turn black, their bones weaken and, as they age, they hunch over at the waist. Most work 12- to 15-hour days until they die of malnutrition-related illnesses, usually around the age of 50. Allowed just one set of clothes, they live and die in rags, without soap, socks, underclothes or sanitary napkins. The camps have never been visited by outsiders, so these accounts cannot be independently verified. But high-resolution satellite photographs, now accessible to anyone with an Internet connection, reveal vast labor camps in the mountains of North Korea. The photographs corroborate survivors' stories, showing entrances to mines where former prisoners said they worked as slaves, in-camp detention centers where former guards said uncooperative prisoners were tortured to death and parade grounds where former prisoners said they were forced to watch executions. Guard towers and electrified fences surround the camps, photographs show. 'We have this system of slavery right under our nose,' said An Myeong Chul, a camp guard who defected to South Korea. 'Human rights groups can't stop it. South Korea can't stop it. The United States will have to take up this issue at the negotiating table.' But the camps have not been discussed in meetings between U.S. diplomats and North Korean officials. By exploding nuclear bombs, launching missiles and cultivating a reputation for hair-trigger belligerence, the government of Kim Jong Il has created a permanent security flash point on the Korean Peninsula -- and effectively shoved the issue of human rights off the negotiating table. 'Talking to them about the camps is something that has not been possible,' said David Straub, a senior official in the State Department's office of Korean affairs during the Bush and Clinton years. There have been no such meetings since President Obama took office. 'They go nuts when you talk about it,' said Straub, who is now associate director of Korean studies at Stanford University. Nor have the camps become much of an issue for the American public, even though annotated images of them can be quickly called up on Google Earth and even though they have existed for half a century, 12 times as long as the Nazi concentration camps and twice as long as the Soviet Gulag. Although precise numbers are impossible to obtain, Western governments and human groups estimate that hundreds of thousands of people have died in the North Korean camps. North Korea officially says the camps do not exist. It restricts movements of the few foreigners it allows into the country and severely punishes those who sneak in. U.S reporters Laura Ling and Euna Lee were sentenced last month to 12 years of hard labor, after being convicted in a closed trial on charges of entering the country illegally. North Korea's gulag also lacks the bright light of celebrity attention. No high-profile, internationally recognized figure has emerged to coax Americans into understanding or investing emotionally in the issue, said Suzanne Scholte, a Washington-based activist who brings camp survivors to the United States for speeches and marches. 'Tibetans have the Dalai Lama and Richard Gere, Burmese have Aung San Suu Kyi, Darfurians have Mia Farrow and George Clooney,' she said. 'North Koreans have no one like that.' Before guards shoot prisoners who have tried to escape, they turn each execution into a teachable moment, according to interviews with five North Koreans who said they have witnessed such killings. Prisoners older than 16 are required to attend, and they are forced to stand as close as 15 feet to the condemned, according to the interviews. A prison official usually gives a lecture, explaining how the Dear Leader, as Kim Jong Il is known, had offered a 'chance at redemption' through hard labor. The condemned are hooded, and their mouths are stuffed with pebbles. Three guards fire three times each, as onlookers see blood spray and bodies crumple, those interviewed said. 'We almost experience the executions ourselves,' said Jung Gwang Il, 47, adding that he witnessed two executions as an inmate at Camp 15. After three years there, Jung said, he was allowed to leave in 2003. He fled to China and now lives in Seoul. Like several former prisoners, Jung said the most arduous part of his imprisonment was his pre-camp interrogation at the hands of the Bowibu, the National Security Agency. After eight years in a government office that handled trade with China, a fellow worker accused him of being a South Korean agent. 'They wanted me to admit to being a spy,' Jung said. 'They knocked out my front teeth with a baseball bat. They fractured my skull a couple of times. I was not a spy, but I admitted to being a spy after nine months of torture.' When he was arrested, Jung said, he weighed 167 pounds. When his interrogation was finished, he said, he weighed 80 pounds. 'When I finally got to the camp, I actually gained weight,' said Jung, who worked summers in cornfields and spent winters in the mountains felling trees. 'Most people die of malnutrition, accidents at work, and during interrogation,' said Jung, who has become a human rights advocate in Seoul. 'It is people with perseverance who survive. The ones who think about food all the time go crazy. I worked hard, so guards selected me to be a leader in my barracks. Then I didn't have to expend so much energy, and I could get by on corn.' Human rights groups, lawyers committees and South Korean-funded think tanks have detailed what goes on in the camps based on in-depth interviews with survivors and former guards who trickle out of North Korea into China and find their way to South Korea. The motives and credibility of North Korean defectors in the South are not without question. They are desperate to make a living. Many refuse to talk unless they are paid. South Korean psychologists who debrief defectors describe them as angry, distrustful and confused. But in hundreds of separate interviews conducted over two decades, defectors have told similar stories that paint a consistent portrait of life, work, torment and death in the camps. The number of camps has been consolidated from 14 to about five large sites, according to former officials who worked in the camps. Camp 22, near the Chinese border, is 31 miles long and 25 miles wide, an area larger than the city of Los Angeles. As many as 50,000 prisoners are held there, a former guard said. There is a broad consensus among researchers about how the camps are run: Most North Koreans are sent there without any judicial process. Many inmates die in the camps unaware of the charges against them. Guilt by association is legal under North Korean law, and up to three generations of a wrongdoer's family are sometimes imprisoned, following a rule from North Korea's founding dictator, Kim Il Sung: 'Enemies of class, whoever they are, their seed must be eliminated through three generations.' Crimes that warrant punishment in political prison camps include real or suspected opposition to the government. 'The camp system in its entirety can be perceived as a massive and elaborate system of persecution on political grounds,' writes human rights investigator David Hawk, who has studied the camps extensively. Common criminals serve time elsewhere. Prisoners are denied any contact with the outside world, according to the Korean Bar Association's 2008 white paper on human rights in North Korea. The report also found that suicide is punished with longer prison terms for surviving relatives; guards can beat, rape and kill prisoners with impunity; when female prisoners become pregnant without permission, their babies are killed. Most of the political camps are 'complete control districts,' which means that inmates work there until death. There is, however, a 'revolutionizing district' at Camp 15, where prisoners can receive remedial indoctrination in socialism. After several years, if they memorize the writings of Kim Jong Il, they are released but remain monitored by security officials. Since it offers a safe haven to defectors, South Korea is home to scores of camp survivors. All of them have been debriefed by the South Korean intelligence service, which presumably knows more about the camps than any agency outside of Pyongyang. But for nearly a decade, despite revelations in scholarly reports, TV documentaries and memoirs, South Korea avoided public criticism of the North's gulag. It abstained from voting on U.N. resolutions that criticized North Korea's record on human rights and did not mention the camps during leadership summits in 2000 or 2007. Meanwhile, under a 'sunshine policy' of peaceful engagement, South Korea made major economic investments in the North and gave huge, unconditional annual gifts of food and fertilizer. The public, too, has been largely silent. 'South Koreans, who publicly cherish the virtue of brotherly love, have been inexplicably stuck in a deep quagmire of indifference,' according to the Korean Bar Association, which says it publishes reports on human rights in North Korea to 'break the stalemate.' Government policy changed last year under President Lee Myung-bak, who has halted unconditional aid, backed U.N. resolutions that criticize the North and tried to put human rights on the table in dealing with Pyongyang. In response, North Korea has called Lee a 'traitor,' squeezed inter-Korean trade and threatened war. An Myeong Chul was allowed to work as a guard and driver in political prison camps because, he said, he came from a trustworthy family. His father was a North Korean intelligence agent, as were the parents of many of his fellow guards. In his training to work in the camps, An said, he was ordered, under penalty of becoming a prisoner himself, never to show pity. It was permissible, he said, for bored guards to beat or kill prisoners. 'We were taught to look at inmates as pigs,' said An, 41, adding that he worked in the camps for seven years before escaping to China in 1994. He now works in a bank in Seoul. The rules he enforced were simple. 'If you do not meet your work quota, you do not eat much,' he said. 'You are not allowed to sleep until you finish your work. If you still do not finish your work, you are sent to a little prison inside the camp. After three months, you leave that prison dead.' An said the camps play a crucial role in the maintenance of totalitarian rule. 'All high-ranking officials underneath Kim Jong Il know that one misstep means you go to the camps, along with your family,' he said. Partly to assuage his guilt, An has become an activist and has been talking about the camps for more than a decade. He was among the first to help investigators identify camp buildings using satellite images. Still, he said, nothing will change in camp operations without sustained diplomatic pressure, especially from the United States. The U.S. government has been a fickle advocate. In the Clinton years, high-level diplomatic contacts between Washington and Pyongyang focused almost exclusively on preventing the North from developing nuclear weapons and expanding its ballistic missile capability. President George W. Bush's administration took a radically different approach. It famously labeled North Korea as part of an 'axis of evil,' along with Iran and Iraq. Bush met with camp survivors. For five years, U.S. diplomats refused to have direct negotiations with North Korea. After North Korea detonated a nuclear device in 2006, the Bush administration decided to talk. The negotiations, however, focused exclusively on dismantling Pyongyang's expanded nuclear program. In recent months, North Korea has reneged on its promise to abandon nuclear weapons, kicked out U.N. weapons inspectors, exploded a second nuclear device and created a major security crisis in Northeast Asia. Containing that crisis has monopolized the Obama administration's dealings with North Korea. The camps, for the time being, are a non-issue. 'Unfortunately, until we get a handle on the security threat, we can't afford to deal with human rights,' said Peter Beck, a former executive director of the U.S. Committee for Human Rights in North Korea. Kim Young Soon, once a dancer in Pyongyang, said she spent eight years in Camp 15 during the 1970s. Under the guilt-by-association rule, she said, her four children and her parents were also sentenced to hard labor there. At the camp, she said, her parents starved to death and her eldest son drowned. Around the time of her arrest, her husband was shot for trying to flee the country, as was her youngest son after his release from the camp. It was not until 1989, more than a decade after her release, that she found out why she had been imprisoned. A security official told her then that she was punished because she had been a friend of Kim Jong Il's first wife and that she would 'never be forgiven again' if the state suspected that she had gossiped about the Dear Leader. She escaped to China in 2000 and now lives in Seoul. At 73, she said she is furious that the outside world doesn't take more interest in the camps. 'I had a friend who loved Kim Jong Il, and for that the government killed my family,' she said. 'How can it be justified?' Special correspondent Stella Kim contributed to this report. 