An inebriated Russian professor has admitted to murdering his lover after he was caught in a river with a backpack containing a woman's arms.

Oleg Sokolov was drunk and fell into the Moika River in Saint Petersburg on Saturday as he tried to dispose of body parts, according to local media.

Police then searched the 63-year-old's home and reportedly found the decapitated body of Anastasia Yeshchenko, 24, his lover and former student, with whom he had written a number of works.

Professor Sokolov, a Napoleon expert at St Petersburg State University who has received France's Légion d'Honneur, has now admitted his guilt and regrets what he has done, his lawyer Alexander Pochuyev told AFP.

He reportedly told police that he killed Ms Yeshchenko during an argument and then sawed off her head, arms and legs.

The professor, who also regularly dresses up as the revolutionary French military leader, is said to have planned to dispose of the body before publicly killing himself while in the costume.

Ms Yeshchenko studied French history and also enjoyed wearing period costumes.

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

“We learn with horror […] of the atrocious crime of which Oleg Sokolov is guilty. We could never imagine that he could commit such an odious act,” it said in a statement.

“We remove him with immediate effect […] and we send our condolences and support to the victim’s family."