Left: Suspect Nikita Rasskazov, 16. Right: Victim Artyom Shustov, 19. The Siberian Times

A 19-year-old Russian was reportedly stabbed and beheaded by a 16-year-old kick-boxer who accused him of forcing himself on his girfriend. Victim Artyom Shustov went to meet the murder suspect – who cannot be named for legal reasons – in a park in the eastern city of Komsomolsk-on-Amur where they argued over the 17-year-old girl.

According to reports in the local media, the girl became friendly with Shustov at a party but then got scared and told her boyfriend that Shustov had been pestering her. However, friends reportedly told Russian papers that she kissed him first.

The Sun quoted one friend as saying: "We were then in the apartment with them and personally saw what was happening. The next day, [the girl] obviously regretted what had happened and she told her boyfriend. Yet she explained it as if Artyom had harassed her and tried to rape her."

According to witnesses, Shustov told the suspect that the girl had "started pestering him at the party, and he was drunk and could not resist her," Fox News reports.

The two teens had a furious row and the 16-year-old pulled out a knife, at which point Shustov tried to run away. He was stabbed in the back and had his head cut off while he was alive.

According to Russian newspaper Dvnovosti, the youth "took the severed head by the hair, put it in a garbage bag, and then into a backpack." He then reportedly visited the girl the following day, pulling the head from the bag as a surprise to show his love. Police have interviewed the girl, who was distraught. The alleged killer ultimately threw the head in the River Silinka, but later confessed.

Russia's equivalent of the FBI, the Investigative Committee, confirmed an investigation is underway. It is expected the 16-year-old will be charged with murder.