Russian investigators said Wednesday they have ended a probe into the 2006 contract-style killing of journalist Anna Politkovskaya, a fierce critic of former president Vladimir Putin's rule.
Investigators charged three Chechen men with the murder and an agent of Russia's Federal Security Services (FSB) of collaborating, reported dpa.
The investigative committee "announces the end of all investigative action and the termination of preliminary inquest," police spokesman Vladimir Markin was quoted by news agency Interfax as saying on Wednesday.
The committee's statement did present a possible motive for the murder.
The four accused Wednesday have been in custody since August when seven other suspects were arrested in what Prosecutor General Yuri Chaika hailed as a major breakthrough in the case.
But suspicions that the Kremlin could be linked with Politkovskaya's death multiplied as several suspects were released on the grounds of alibis.
Politkovskaya's former editor-and-chief at Novaya Gazeta said Wednesday it was too early to close the investigation.
"It is impossible to interpret this as the end of the inquest ... The murderer still is at large, and no one who ordered the killing has been identified," Dmitry Muratov said on Wednesday.
Politkovskaya, 48, who reported on human rights abuses by Russian soldiers in war-ravaged Chechnya, was gunned down outside her Moscow flat on October 7, 2006.