MOSCOW -- A Russian human rights activist has been questioned by investigators after he said there were signs a suspect in opposition politician Boris Nemtsov's killing was tortured.
Andrei Babushkin, a member of the Kremlin human rights council, said that federal investigators had questioned him on March 12 "as a witness in the case of Boris Nemtsov's murder."
He said Investigative Committee officers told him that because he is witness, he is now barred from visiting suspects in the case.
After visiting Zaur Dadayev and two other suspects in pretrial detention at Moscow's Lefortovo jail, Babushkin said on March 11 that there was reason to believe Dadayev "confessed under torture."
He said then that he had seen "numerous wounds" on Dadayev's body.
Dadayev, a former police officer in the volatile Chechnya region, is one of five suspects in custody over the fatal shooting of Nemtsov, a vocal critic of President Vladimir Putin, near the Kremlin on February 27.
The newspaper Moskovsky Komsomolets (MK), whose journalist visited three of the suspects along with Babushkin, quoted Dadayev as saying he had confessed because he was told a man detained with him would be released if he did so.
Moscow's Basmanny District Court said on March 12 that Dadayev's lawyer had filed an appealed against his client's pretrial detention on March 11.
At an arraignment hearing on March 8, the judge said that Dadayev had confessed to involvement in Nemtsov's slaying, but he did not admit guilt in the courtroom.
Babushkin is a member of the Presidential Council on Development of Civil Society and Human Rights, an advisory body whose members meet occasionally with Putin.
He said investigators asked him about the whereabouts of the journalist, Yeva Merkachyova, and told him they went to her home in hopes of questioning her but did not find her there.
The Investigative Committee said March 11 that Babushkin and Merkachyova had violated the law by revealing details about their meetings with the suspects and could face prosecution.
Nemtsov, 55, was hit by four bullets to the back as he walked across a bridge just off Moscow's Red Square with a girlfriend from Ukraine shortly before midnight.
The most prominent politician killed in Russia since the 1990s, Nemtsov had led protests, published reports alleging corruption among allies of Putin, and vocally opposed Moscow's support for separatists whose conflict with government forces has killed more than 6,000 people in eastern Ukraine.
His killing underscored the risks run by Russians who challenge the government and drew calls from the West for a thorough investigation -- something former colleagues of Nemtsov fear will not take place because it could lead too close to the Kremlin.
Nemtsov’s eldest daughter, Zhanna Nemtsova, told the BBC on March 12 that Putin was "politically" to blame for her father's death.
Speaking from Italy, Nemtsova, 30, said that her father was "a critic of Putin, he fought with Putin, with nobody else."
"After his death, the opposition is beheaded and everybody is frightened," she said.
The Investigative Committee said on February 28 that one possible motive for Nemtsov's killing could have been anger over his position on the deadly Islamist militant attack in January on Charlie Hebdo, a French magazine that published caricatures of the Prophet Muhammad.
The Kremlin-backed head of Chechnya, Ramzan Kadyrov, defended Dadayev in a statement posted on Instagram on March 8, calling him a "true patriot" and a deeply pious Muslim who was shocked by the cartoons.
Lawyers and allies of Nemtsov have said they do not believe that anger over the Charlie Hebdo cartoons or Nemtsov's position on the issue was the motive in his killing.