A Russian history expert has admitted he murdered his young lover before dismembering her body.

Professor Oleg Sokolov was arrested yesterday on suspicion of murder after he was dragged from a freezing river carrying two severed arms in a backpack.

The young woman - identified by police sources as 24-year-old Anastasia Yeschenko had been a student of Sokolov's at St Petersburg State University.

Students at the university have since described Sokolov as a 'freak', stating he would often do impression of Napoleon and would call his lover 'Josephine'.

Sokolov's lawyer Alexander Pochuev, said that Sokolov 'has admitted his guilt' and regrets what he has done.

Professor Oleg Sokolov (right) has admitted killing 24-year-old Anastasia Yeschenko (left)

Sokolov was a professor at St Petersburg University and would often dress up as Napoleon (he is pictured above in 2012 wearing a costume dating back to the 1812- era

Rescuers examine the bottom of the Moika River today where were the remains were found

Sokolov was reportedly drunk and fell in as he tried to dispose of body parts.

After disposing of the corpse he reportedly planned to commit suicide at the Peter and Paul Fortress, one of the former imperial capital's most famous landmarks, dressed as Napoleon.

Anastasia had been in a relationship with the historian, 63, when he 'accidentally killed her' following an argument, according to the report which stated he had confessed to police.

The relationship was said to have been an 'open secret'.

Multiple reports say the academic is in detention in hospital suffering from hypothermia.

A decapitated head and a body along with a saw covered in blood were later found at Sokolov's flat in St Petersburg

A former student also claimed that Sokolov was dedicated to his work but was also emotionally unstable and abused alcohol.

He was dragged from the icy Moyka River in St Petersburg in the early hours of Saturday morning.

In his backpack were two female arms severed at the elbow and a gun.

The gruesome corpse and a severed head were found at his nearby apartment on Moyka Embankment, say reports.

Sokolov is considered a leading Russian expert on the Napoleonic Wars and is a professor at St Petersburg State University.

He is well known for reenacting moments of Napoleonic history.

The historian, who also taught at Sorbonne University, is the author of books on French emperor Napoleon Bonaparte.

He acted as a historical consultant on several films and took part in historical re-enactments of Napoleonic wars.

Ms Yeschenko had been in a relationship with the historian, 63, when he 'accidentally killed her' following an argument, according to the report which stated he had confessed to police

Multiple reports say the academic is in detention in hospital suffering from hypothermia

Both he and his lover studied French history and liked to wear period costumes, with Sokolov dressing up as Napoleon.

Sokolov was president of the Russian Association of Military History and is now a member of the body's scientific council.

He has worked as a technical adviser to European television broadcasters on films depicting the Napoleonic era, and he was made a knight of the Legion of Honour in France in 2003.

Sokolov was president of the Russian Association of Military History and is now a member of the body's scientific council

Sokolov is considered a leading Russian expert on the Napoleonic Wars and is a professor at St Petersburg State University

Pictured: Moyka river embankment, where Sokolov was found with two severed arms in his backpack