A journalist has died after being beaten in police custody, the latest in a string of scandals involving violence and corruption among Russian law-enforcement officers.

The 47-year-old victim was hospitalized on January 4 with severe injuries to internal organs after being beaten by an officer in a police holding cell for drunks in the Siberian city of Tomsk, the federal Investigative Committee said.

He died without emerging from a coma, the committee said.

State-run RIA and other Russian news agencies said the victim was a journalist, and Ekho Moskvy radio identified him as Konstantin Popov.

The holding cell employee, Alexei Mitayev, has been charged with aggravated assault and abuse of authority.

Attacks on Russian journalists who challenge the authorities or seek to expose corruption are frequent, but there was no immediate indication that the victim's work was a motive.

Mitayev, 26, admitted to the beating and cited stress, Russian media reported. The reports said he has been dismissed.

Recent outbursts of police violence have added to widely negative perception of law enforcement officers in Russia, fuelled by mounting evidence of corruption.

In recent months, several police officers have publicly alleged corruption among their superiors and colleagues.

Last month, President Dmitry Medvedev said police misconduct was sparking public anger and undermining the state's authority.

He called for serious reform and ordered the 1.4 million-strong Interior Ministry staff cut by 20 per cent by 2012.

- Reuters