A jealous Russian teenager hacked off the head of his love rival, then took it to show his “distraught” girlfriend to prove his love for her, police have said.

The 16-year-old kickboxer is reported to have asked to meet Artyom Shustov, 19, in a park in the eastern Russian city of Komsomolsk-on-Amur, where the pair got into a furious row.

The younger teen accused the older one of forcing himself on his girlfriend, 17, at a party.

Shustov insisted the girl had “started pestering him at the party, and he was drunk and could not resist her,” according to Russian newspapers which cited police sources and witnesses.

The pair began fighting and the younger teen took out a kitchen knife from his backpack and twice stabbed his rival in the back and abdomen, it is claimed.

With Shustov still alive but badly wounded, the younger teen is said to have then “started to cut off his head with the knife.”

He then “took the severed head by the hair, put it in a garbage bag, and then into a backpack,” reported newspaper DVnovosti.

Another paper, the Siberian Times, reported: “He dragged the body to another part of the park and put Artyom’s student papers on his chest.

“Then he went home, hid his bloodstained clothes in his wardrobe, took a shower and went to bed.”

The next day, the alleged killer is said to have paid his girlfriend a visit — telling her about the murder and giving her the grisly present of his rival’s severed head.

Police said the teen “wanted to bring the head to his beloved [girlfriend] to prove his love in this way,” adding that the 16-year-old later confessed to the beheading in a formal statement.

Police have interviewed the “distraught” girl, but no further details have been given.

She has not commented on the grisly killing.

After showing her the severed head, the teen tried to hide it, police sources claim.

“He put some stones in the backpack with the head and threw it to the River Silinka,” reported DVnovosti.

A month before the killing, the girl had posted an image of her and Shustov together, possibly at the party which led to the row.

Friends have told police the girl had admitted to her boyfriend that she had cheated on him with Shustov — but claimed he had forced himself on her.

But in fact, the friends said, she had started kissing him and had initiated their tryst.

“We were then in the apartment with them and personally saw what was happening,” said one friend.

“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,” reported the local newspaper.

After speaking and arranging to meet at the entrance of the park, Shustov arrived with a female friend called Daria — but she apparently left when the pair started to argue.

Witnesses at Railway Workers Park in the city of 260,000 people said the older teen tried to flee when he saw his rival had a knife.

The 16-year-old was detained and police confirmed his confession, with charges expected to follow.

The Investigative Committee — the Russian equivalent of the FBI — confirmed a murder probe is under way.

A friend said: “[The alleged killer] was spending a lot of time in online groups devoted to maniacs and often carried a knife with him.”

A close pal of the dead man said: “He had no enemies, ever.”