MOSCOW — A member of the Kremlin’s advisory council on human rights said on Wednesday that the main suspect in the shooting death of a high-profile opposition figure was most likely forced to confess under duress, and that his two cousins in detention had been tortured.

After visiting the three Chechens, who were among five suspects imprisoned on Sunday in Lefortovo Prison in Moscow, Andrei Babushkin, a rights activist, said that the men had suffered multiple injuries after their arrest.

In a summary of the visit posted on the council’s website, Mr. Babushkin also reported that another man arrested at the same time as Zaur S. Dadayev, the main suspect, had disappeared and said that he had askedRussia’s top law enforcement agency to account for his whereabouts.

The 40-member presidential council — officially the Council Under the President of the Russian Federation for the Development of Civil Society and Human Rights — has a reputation for a certain degree of independence and a real interest in some human rights issues like the treatment of prisoners. Not all members sign every statement, but rights experts said overall committee members do serious, trusted work.

The report caused an immediate stir in the Russian government. The Investigative Committee, which is responsible for looking into the Feb. 27 killing of the opposition figure, Boris Y. Nemtsov, near the Kremlin, accused Mr. Babushkin and Eva Merkacheva, another rights official, of violating the law.

David Fuller's view

Clearly there are some people in Russia who do not believe Putin’s propaganda, are offended by it and will not remain silent despite considerable risk to themselves.  This is important because Putin’s government is the biggest threat to peace in Europe and economic development in the Eastern region.