"It does not matter whether the crime committed by the detainee is serious. In fact, it does not matter whether the detainee committed the crime. All kinds of people fall victim to this terrible human rights abuse."
The group's 196-page report on five Russian regions said police often beat victims to extract confessions, which courts accept as grounds for conviction. Official figures claim there are one million Russians in jail and 300,000 in pre-trial detention.
The report, called Confessions At Any Cost, described various tortures including the "lastochka" or swallow, when the victim is handcuffed and hung up to be beaten. Police call another the "konvertik" or little envelope. The detainee is forced into an excruciating position, the head between the knees and hands tied to the feet.
The "slonik" or little elephant, involves asphyxiating the suspect by putting a gas mask over the face and turning off the oxygen. The hose of the mask is said to resemble an elephant's trunk.
Boris Botvinnik, from Volgograd, a maths PhD student at Moscow University, said police burst into his flat and knocked him down, punching and kicking him. They put on the gas mask until the innocent student confessed to a robbery. The only witness to the crime had left Russia without even being questioned. Mr Botvinnik was jailed for five years, but prison doctors said he was losing his sight because of the torture. The term was suspended and he was released.
Diederik Lohman, a Human Rights Watch executive in Moscow, said: "It is hardly surprising many Russians are more afraid of the police than of criminals."