Just days after Russian diplomats in the U.K. publicly celebrated the deaths of dozens of captive members of Ukraine’s Azov regiment killed at a Russian-controlled penal colony, Russia’s Supreme Court has declared the regiment a terrorist organization. The ruling came after some bizarre testimony by a Russian official who claimed Azov members are actually cannibals. “They practice cannibalism in Azov. One of the captive fighters said that in his testimony,” said Georgy Volkov, the chairman of the public monitoring commission of Moscow, who served as a witness for Russian prosecutors, according to TASS. The court handed down its decision a short time after Volkov’s testimony, in a move that is likely to muck up any negotiations for a prisoner swap. Hundreds of Azov fighters who spent weeks fending off Russian troops at Mariupol’s Azovstal steel plant are now in Russian captivity after the siege ended with their surrender in mid-May. Hundreds more are being held on Russian-controlled territory in Ukraine’s Donbas. Dozens of them were killed last week in an attack on the penal colony where they were being held in Olenivka. Ukrainian authorities say the attack was an inside job, with Russian forces slaughtering the prisoners to cover up war crimes.