Kirill Popov, the first deputy head of the Russian Federal Penitentiary Service's Moscow branch, is likely to have overseen the work of the Olenivka POW camp, located in the occupied parts of Donetsk Oblast.
The facility held Ukrainian prisoners of war (POWs) and civilian hostages whom the Russians captured in Mariupol in May 2022.
Former detainees reported horrendous conditions of detention and systematic torture. The UN Human Rights Monitoring Mission in Ukraine also confirmed the inhuman treatment of prisoners of war in Olenivka, 20 kilometers southwest of occupied Donetsk.
The Kyiv Independent obtained Popov's phone records and geolocated his coordinates.
These records suggest that Popov likely visited the occupied part of Donetsk Oblast between May 16 and June 17, 2022.
On May 16, over 2,000 Ukrainian soldiers, who were defending Mariupol's last stronghold, surrendered and were transferred to the POW camp in Olenivka. Three Ukrainian soldiers confirmed to have seen Popov in the POW camp.
He was giving orders and coordinating the work of other prison staff, former prisoners of war told the Kyiv Independent on conditions of anonymity.
During this time, Popov communicated with Rustam Stepanenko, first deputy director of the Russian Federal Penitentiary Service, and representatives of the Russian-led proxies that oversee POWs.
In June 2022, Russian government-controlled media reported on the growing cooperation between prison systems in occupied areas of Donetsk Oblast and Russia.
Some reports featured a picture of officials gathered for a meeting, including Popov, referred to as "the commander of the grouping of the Federal Penitentiary Service of Russia in the (so-called) Donetsk People's Republic."
This image provided additional evidence that Popov was in the occupied part of Donetsk Oblast during the summer of 2022.
The Kyiv Independent called Popov, but he declined to comment on his role in the Olenivka POW camp.
On July 29, 2022, an explosion occurred at the Olenivka camp, killing 57 prisoners of war and injuring over 100.
The UN July investigation concluded that Russian claims of Ukrainian involvement in the explosion are false.
Ukrainian officials have claimed that the explosion was Russian-made and conducted from within the prison.