A BBC World Service investigation has identified individuals accused of running Russia's secretive "torture prisons" in occupied Ukraine, a detention system that human rights bodies say has abused thousands of civilians. The inquiry named Yurii Temerbek, a former Ukrainian traffic policeman who joined Russian-backed separatists, alongside two other men accused of mistreating detainees. The findings matter because the system operates almost entirely beyond the reach of Ukrainian and international justice, and survivors regard the public exposure of their alleged abusers as a rare step towards accountability.

The account centres on Liudmyla Huseinova, a 64-year-old detained for over three years after being accused of spying, who describes torture and sexual assault at the notorious Izolyatsia detention centre in Donetsk. The UN's human rights office says torture and ill-treatment of civilians in the system is "systematic and widespread", citing beatings, electric shocks, mock executions and sexual violence; Russia dismisses such allegations as "groundless lies". Ukrainian authorities say more than 16,000 civilians have been taken captive or have disappeared since 2014. The BBC worked with Ukrainian open-source investigators to trace Temerbek, who now appears to live an ordinary family life in Russia's Rostov region and faces Ukrainian criminal proceedings.