Ukrainian prisoners of war say they were tortured at Russian prison

Ukrainian prisoners of war have said they were subjected to torture, including frequent beatings and electric shocks, while held in Russia, a BBC investigation has heard.

A dozen former captives described extreme violence and ill-treatment, apparent violations of international humanitarian law. Many of them surrendered in the city of Mariupol last year.

They were taken to a detention facility in the southern Russian city of Taganrog - before being released in exchanges.

Russia's defence ministry did not respond to several requests to comment on the allegations. It has previously denied torturing or mistreating captives.