Three men on trial for helping murder Kremlin critic Anna Politkovskaya were just pawns and the real killers are at large, a lawyer for Politkovskaya's family told the trial on Monday.

The murder of Politkovskaya, an investigative reporter who reported on human rights abuses, provoked an outcry in the West and raised concerns about the dangers to reporters and rights campaigners in Russia.

Two Chechen brothers, Dzhabrail and Ibragim Makhmudov, are charged with helping guide the killer to Politkovskaya and former police officer Sergei Khadzhikurbanov is accused of providing technical help. All three say they are innocent.

Rustam Makhmudov, suspected of shooting Politkovskaya outsider her apartment in 2006, is on the run. Prosecutors have never identified who ordered the killing.

"The whole thing has been organised at a high level, not at the level of the defendants," lawyer Karina Moskalenko told the jury in a Moscow courtroom as legal teams in the lengthy trial began their closing arguments.

"I will never believe the Chechen boys had their own reasons (to kill Politkovskaya)," she said. "I have drawn my own conclusion that the boys have been used by someone. The question is whether they knew or not."

Politkovskaya, a mother of two who was 48 when she was killed, had won prominence for attacking what she saw as Russia surrendering its democratic freedoms under Vladimir Putin, who was president until last year.

Human rights abuses and corruption in the North Caucasus region, which includes Chechnya, were a target of her criticism, infuriating officials in the region as well as in Moscow.

Putin, now serving as prime minister, has rejected suggestions in the West that the Kremlin could have been behind Politkovskaya's killing. Russian officials say the murder was an attempt to discredit the Kremlin.

But addressing jury members, Moskalenko appeared to direct the blame for the murder at the authorities.

"Who could hate Anya (Politkovskaya) for her articles? Those who are responsible for what was happening in Chechnya," she said, without identifying any individuals.