Wang Guoqi, 38, speaking to congressmen, confirmed that condemned men, and sometimes women, are executed to order so that their organs can be transplanted into wealthy recipients from the West and Far East.
Dr Wang was a burns specialist at the Paramilitary Police Hospital in Tianjin, under the control of the People's Liberation Army, whose senior generals are believed to make large profits from the trade. He claims that after execution, bodies were taken to the hospital where every part that could be sold was stripped from the corpse.
Dr Wang's job was to take skin and corneas, a task he says he performed at least 100 times at the hospital. He claims that prisoners sentenced to death were matched with potential donors and sentence delayed until the patient had arrived in China and was ready for the transplant operation.
He described envelopes with cash being handed over to all those involved, including court officials and prison staff. His team would usually be taken in unmarked cars to the crematorium, where bodies were waiting, hands tied behind their backs. Papers on the bodies, detailing each case, made no mention of the prisoners giving consent for their organs to be taken.
In the most macabre incident, he described how an execution by firing squad was organised so that the bullets would not damage the man's kidneys. Dr Wang says that after another team had removed the kidneys, he arrived to harvest the victim's skin, only to find that "the prisoner was still breathing and his heart continued to beat".
After removing some of the skin from the still-living man, his burns unit team gave up. He said: "The half-dead corpse was thrown into a plastic bag on to the flatbed crematorium truck." The incident left him with "horrible recurring nightmares".