A well-known Russian historian has confessed to murdering his lover – a former student – his lawyer says, after he was found in a river with a backpack containing a woman’s arms.

Oleg Sokolov, 63, was drunk and fell into the river as he tried to dispose of body parts, Russian media said.

Police then found the decapitated body of Anastasia Yeshchenko, 24, at his home in the city of St Petersburg.

“He has admitted his guilt,” his lawyer Alexander Pochuyev told AFP, adding that he regretted what he had done and was now cooperating.

Prof Sokolov reportedly told police that he killed his lover during an argument and then sawed off her head, arms and legs.

He is said to have planned to get rid of the body before publicly committing suicide dressed as Napoleon.

Mr Pochuyev said Prof Sokolov – who has been receiving hospital treatment for hypothermia – may have been under stress.

The historian has written several books on Napoleon and also acted as a historical consultant on several films. He and Ms Yeshchenko had co-authored several works.

Both he and Ms Yeshchenko studied French history and enjoyed wearing period costumes, with Prof Sokolov dressing up as Napoleon.

Students described him as both a talented lecturer who spoke French and did impressions of Napoleon and as a “freak” who called his lover “Josephine” and asked to be addressed as “Sire”, AFP reported.

He was also a member of France’s Institute of Social Science, Economics and Politics (Issep), which on Saturday said it had removed him from his position on its scientific committee.

“We learn with horror… the atrocious crime of which Oleg Sokolov is guilty,” it said in a statement.

“We could never imagine that he could commit such an odious act,” the statement added.

Issep was founded by Marion Maréchal, the niece of far-right National Rally party leader Marine Le Pen and a former lawmaker for the far-right National Front party.