In an interview, a British man who was released through a prisoner exchange in the Ukraine war reported that he was tortured in Russian captivity.

He was repeatedly beaten with a baton during interrogations and forced to sing the Russian national anthem, Aiden Aslin told Britain’s The Sun newspaper (Sunday edition). Aslin is one of five Brits who were flown out of Russian captivity to Riyadh on Wednesday.

The 28-year-old from Nottinghamshire in central England was living in Ukraine at the start of the war and served in the local military. He was captured in fighting around Kyiv and sentenced to death in June by pro-Russian separatists in Donetsk as a mercenary.

Aslin said he was hit in the forehead during an interrogation and then fell to the ground. An officer knelt down next to him and said in Russian: “I am your death.” The man then pointed to Aslin’s back. “He showed me his knife and I realized he stabbed me with it,” said the 28-year-old, who showed multiple scars on his back.

Aslin said he was locked in a solitary cell with lice, cockroaches and no natural light and was “treated worse than a dog”. The newspaper wrote that his guards “played the Russian national anthem on a continuous loop” and forced him, under threat of further beatings, to stand up and sing along.

Aslin was freed as part of a prisoner exchange between Russia and Ukraine. The prisoners from Russia were transferred to Saudi Arabia. Ukraine had accused Russia of torture shortly after the exchange.