Surviving Ukrainian prisoners of war have given sickening accounts of their torture at the hands of “Doctor Evil,” a notorious Russian medic at the heart of Vladimir Putin’s modern-day gulag system.

Operating out of Russia’s penal facility No. 10 in Mordovia, southeast of Moscow, Ilya Sorokin, 35, has been charged with torturing at least 29 Ukrainian PoWs in absentia by Ukraine’s SBU security service.

One former PoW described how the sadistic doctor would order them to strip off before subjecting them to cruel and degrading acts.

“There were 30 of us, all naked, in a room. He asked who had asthma, tuberculosis, or anything else,” Serhii Doroshenko, a Ukrainian military doctor, told the Times of London.

“But if, God forbid, you mentioned any illness, then he would torture you personally, on top of the torture from the prison staff, because you were making extra work for him,” Doroshenko added, speaking from his hospital bed, where he is still recovering from his injuries.

Doroshenko, captured during a battle for the eastern city of Mariupol in 2022, spent more than 1,000 days in Russian captivity before his release last year in a prisoner exchange.

“He kicked us and hit us with a baton and a stun gun. He knows where it hurts the most, and he deliberately strikes you right there,” Doroshenko said.

He described how Sorokin allegedly reserved his worst punishments for captured Ukrainian medical personnel, over unproven claims that they had carried out medical experiments on Russian troops.

“This myth was spread by Russian propaganda. They told us that in Mariupol medics ran some biological experiments on Russian soldiers and colonels,” Doroshenko said.

“That they had cut off their testicles. This is bulls–t, of course, but we got beaten for this just as much as artillerymen and snipers,” he added.

Other PoWs described how Sorokin, also nicknamed Dr Shocker, would wear a medical mask and sometimes a balaclava with a skull on it during the torture.

“You can’t call him a human being. He started to wave the stun gun around and shocked me several times,” Ukrainian marine infantry officer Pavlo Afisov told RFE/RL.

“He said we were ‘stinking khokhkly [A Russian slur for Ukrainians]’ who did not deserve decent treatment,” Afisov added.

Sorokin is also accused of using a stun gun on Ukrainian PoWs if they failed to shout “Glory to Russian medicine!” or if they asked for help with heart pains, festering wounds, or even a toothache.

Ukrainian inmates were ordered to address Sorokin with their heads down and their hands behind their backs, although some caught glances at his face, Doroshenko said.

“To raise your face was to die, or to receive so many blows that you might not survive,” he said.

The European Union has imposed sanctions on Sorokin, citing his “inhumane and degrading treatment” of prisoners.

Sorokin has denied the allegations against him.

He is far from the only Russian medic accused of torturing Ukrainian PoWs.

Hundreds of former prisoners have recounted witnessing Russian medical professionals “directly participating in torture, ill treatment, and the degrading treatment of detainees,” as part of a new report, “The Anatomy of Torture,” by the Kyiv-based Center for Civil Liberties.