A RUSSIAN teenager is facing castration after being severely beaten by police in the Volga river town of Kstovo.

The doctors now treating the 17-year-old, Nikitin Kaftasev, "are not sure whether they will be able to save his male organs," the Committee Against Torture said in a statement.

Nikitin Kaftasev and a friend were detained and beaten by police on a street in the town centre, before being dragged to police headquarters where beatings continued for hours, the group said, citing the teen's testimony.

"The teenagers were subject to torture and ridicule. Nikitin was kicked in the groin," it said. "According to Nikitin, several policemen were present at the time."

Local prosecutors in the Nizhny Novogorod region, some 500 kilometres east of Moscow, said it would decide whether to launch a probe into the incident.

"We are now carrying out a preliminary check into this, after which there will be a decision on whether to open a criminal probe," against local police, spokesman Yulia Sklyarova said.

The latest report of police brutality comes as Russia's police force grapples with a slew of violent crimes by officers that badly hurt its reputation.

In January, a Russian journalist died from being savagely beaten and raped with a broom by a policeman in the Siberian city of Tomsk, and in Moscow, a lieutenant colonel shot a snow plow driver dead for grazing his car.

Just the month earlier, an investigator in Siberia shot a suspect during questioning.