A Russian cannibal pedophile and his 12-year-old “girlfriend” have been busted for hacking a man to death and then eating his body parts.

Cops say the unnamed 22-year-old accused killer and the girl were living with victim Alexander Popovich, 21, outside of St. Petersburg.

The girl was allegedly a willing participant and was likely groomed online, police said.

The debauched duo “cooked the brains” of Popovich and when cops went looking for him they found his head cooking in the oven of his home.

The man and girl reportedly told investigators: “There was nothing else to eat.”

As for the girl, she was a runaway who had been reported missing but described as looking around 15 or 16 years old.

Online she posted the message: “I love one stalker. I won’t give him away to anyone, he is only mine. I do not need anybody else.”

The accused pedophile reportedly admitted to detectives he was sexually involved with the girl, who had been reported missing 10 days from her home 2,400 km away.

Popovich’s body — minus the head and arms — were discovered by his brother under a white sheet. The dead man had been disemboweled.

“The contents of the frying pan did not look like the fresh meat found at a supermarket,” a law enforcement source told local media.

The dead man’s brother told reporters: “It was a mess there as if the apartment had been robbed. Then I saw something covered with a blanket and in blood. I did not know it was him, I rushed out. I was in a panic.

“My only thought was – please don’t let it be him.”

The girl is below the age of criminal responsibility in Russia and is in care at the Centre for Underage Criminals of St Petersburg.

He faces 25 years in prison on murder and sex crimes charges.

bhunter@postmedia.com