In February this year, a Chechen blogger in hiding in Sweden was viciously assaulted by a man with a hammer as he slept. In the fight that followed, Tumso Abdurakhmanov managed to grab the hammer and defend himself, and filmed the aftermath of the attack and his interrogation of his assailant.

Tumso was the third Chechen to be attacked in Europe in just a few months; he was the only one to survive. All three men were critics and opponents of the pro-Moscow regime in Chechnya, an area in Russia’s volatile North Caucasus mountains where the authorities are accused of serious human rights abuses and violations. For Assignment, Nick Sturdee investigates who may have sent Tumso’s attacker, and explores the blogger’s relations with the Chechen government and leader Ramzan Kadyrov.

What are the parallels with another recent attack, in Berlin, where former Chechen fighter Zelimkhan Khangoshvili was shot dead? A case where the Bellingcat investigative team has identified the killer and revealed his close connections to the Russian Security Services, the FSB.

Listen to the full broadcast at BBC