Zaur Dadayev-- a former Chechen police officer, one of two suspects charged with the murder of Russian opposition politician Boris Nemtsov, "likely confessed under torture", a member of Russia's Human Rights Council says.
Andrei Babushkin, who visited Dadayev on Tuesday, says he saw "numerous wounds" on his body, suggesting he had been tortured.
The suspect himself said he was tied up for two days with a bag over his head.
He says he only confessed so a friend arrested with him would be freed. He planned to tell the truth in court, but was never given a chance to speak.
"There are reasons to believe Zaur Dadayev confessed under torture," Mr Babushkin said after a delegation visited the suspect in prison as Dadayev told the visitors he was mistreated in the two days after his capture in Chechnya on Saturday.
Boris Nemtsov, a former deputy prime minister and Russia's top opposition leader, was shot in the back as he was walking within sight of the Kremlin on Feb 27.