A Russian court on Monday sentenced Alexei Pichugin, the former head of security at the bankrupt Yukos oil group, to life imprisonment in a hard labour camp for a series of murders and attempted killings.

The decision upheld an earlier conviction against Mr Pichugin, who was sentenced last August to 24 years in prison for murder, including the killing in 1998 of the mayor of the town where Yukos had its main oil production base. He had been sentenced to 20 years in a previous murder trial.