Former colleagues of Politkovskaya’s at the Novaya Gazeta newspaper have said they suspect the murder was linked to a report she was preparing into allegations of torture in Chechnya.
She did not give details on the other two suspects.
|Politkovskaya was shot dead at her apartment
building in Moscow last October [File: AP]
The killing drew a wave of international condemnation and prompted concerns about media freedoms in Russia.
More than 80 journalists in Russia have been murdered because of their jobs since 1993, according to the International Federation of Journalists.
Jonah Hull, Al Jazeera’s correspondent in Moscow, said: “She was a massively admired figure here in Russia and internationally.
Putin said last December that everything possible was being done to find and punish her killers.
“The best professionals in Russia’s law enforcement are investigating this crime and we already have certain results,” he said.
A prominent campaigner for press freedom expressed scepticism that prosecutors were any closer to convicting Politkovskaya’s killers.
“The murders of journalists in the past 14 years have been so poorly investigated that it’s hard to have any faith in this,” Oleg Panfilov, head of the Centre for Journalism in Extreme Situations, told Reuters news agency.
“I suspect it’s connected with the fact that the one-year anniversary of [her] death is coming up.