A Russian soldier fighting on the frontlines of Ukraine killed his colleague and lived off his remains for two weeks, Ukraine's military intelligence directorate (HUR) has claimed.

HUR released what it said was an intercepted call between two of Vladimir Putin's troops in which they were heard discussing an alleged case of cannibalism among the ranks.

One soldier was heard telling his stunned comrade in an expletive-laden rant how a soldier nicknamed Brelok - or 'keychain' - killed his fellow infantryman 'Foma' and began eating him.

'F***ing hell... Brelok f***ing ate him, f*** me... nobody went anywhere. Brelok whacked him and then ate him for f***ing two weeks,' the first caller says.

'No f***ing way… holy sh*t… f*** my bald skull. Was Brelok really found as a 200?' the other responds.