Russia has appointed an extra team of investigators to handle the case of murdered journalist Anna Politkovskaya, the prosecutor general's office says.
Politkovskaya's reports exposed abuses of power by officials
The new team will work in parallel with the first team. Sergei Ivanov, a senior investigator, is co-ordinating the two groups, according to the office.
Politkovskaya was a strong critic of President Vladimir Putin - especially his military campaign in Chechnya.
Last week 10 arrests were announced, but at least two have been released.
The Russian Itar-Tass news agency reports that a leading detective, Pyotr Garibyan, is in charge of the new team of investigators.
The prosecutor general's office denied earlier Russian media reports that he had been replaced.
Politkovskaya, a reporter for the newspaper Novaya Gazeta, was shot dead near her Moscow apartment last October.
The murder drew international condemnation, including allegations that President Vladimir Putin was failing to safeguard freedom of speech.
Last week, chief prosecutor Yuri Chaika said 10 suspects - including serving and former security officers - had been arrested in the investigation. Their ringleader was a Chechen gang boss, he said.
But he said there were indications that the murder plot had been masterminded abroad, by people interested in destabilising Russia.
Campaigners for press freedom and former associates of Politkovskaya are sceptical about that theory.
In a BBC interview, Novaya Gazeta's chief editor Dmitri Muratov said Pyotr Garibyan had "solved all the most serious crimes he has investigated".
"If they persuade Garibyan to stay in the investigation team in some capacity, then I will have hope that the Politkovskaya case will continue."
Following Mr Chaika's comments, Russian media reported that two Russian policemen among the 10 people arrested in the case had been released.
Another suspect in the group, a Federal Security Service (FSB) officer, was arrested on an unrelated charge.