North Korean defectors have come forward to charge that the so-called Democratic People’s Republic of Korea has been using political prisoners to test chemical agents. The new allegations were reported by 38 North, the digital publication operated by the U.S.-Korea Institute at Johns Hopkins University's School of Advanced International Studies.

The reports by 38 North cite the testimony of former prison guards, now defectors, who used to work at detention facilities where political prisoners were kept, as well as ordinary prisoners. A man who goes by the pseudonym Kwon Hyok, a former security official at Detention Camp 22, told the institute that prisoners who were in good health were put inside glass chambers that were filled with an unknown “gas” while technicians took notes and observed their deaths. “Normally, a family sticks together and individual prisoners stand separately around the corners,” Kwon said. Kwon’s description of what he saw while on the job seemed to match the commonly reported effects of chemical weapons. “I watched a whole family being tested for suffocating gas and dying in the gas chamber: parents, one son and a daughter,” he recounted. “The parents were vomiting and dying, but until the very last moment they tried to save the kids by doing mouth-to-mouth breathing.”

Another defector, Im Chun Yong, a former special operations soldier, also confirmed that similar experiments were done while he worked on an unnamed island in the Yellow Sea, located off the country’s west coast. According to a report by the Telegraph, Im's allegations matched the reports by a Seoul-based human rights group that claimed the North was testing chemical weapons on disabled children on an island off South Hamyong Province.

However, along with much other North Korean news, 38 North warns that such reports are still extremely difficult to corroborate.

That being said, the report does detail a study that claims North Korea produces chemical agents like hydrogen cyanide, phosgene, sarin, tabun, and chlorine, in addition to a number of mustard gases. North Korea reportedly has the capability to produce roughly 4,500 tons of chemical agents a year, and up to 12,000 in the event of war.

North Korea has also reportedly been the source of chemical agents or chemical agent production technology to countries like Egypt, Iran, Libya and Syria since the 1990s.