Moscow - New suspects are being investigated by Russian justice officials in the case of journalist Anna Politkovskaya, three years after her murder, Politkovskaya's former editor said Tuesday.

Sergey Sokolov, the chief editor of the government-critical daily Novaya Gazeta, was quoted by the Interfax news agency as saying persons previously unnamed by the authorities are being looked into.

The suspected murderer is living in a European Union nation, and enjoying freedom of movement, Sokolov said without divulging his sources or the suspect's name.

Politkovskaya, a Kremlin critic and investigative journalist who reported war crimes in the Russian autonomous region of Chechnya, was shot dead before her home on October 7, 2006.

In February 2009, a jury in a lower Moscow court returned a verdict of acquittal for four suspects on the basis of insufficient evidence tying them to the crime.

Two Chechen brothers Dzhabrail and Ibragim Makhmudov were accused of being accomplices while a former police officer Sergei Khadzhikurbanov was accused of helping the killer get away.

A fourth defendant, Pavel Ryaguzov, an agent of Russia's FSB security service, was acquitted in a separate case, after charged with providing the killer with Politkovskaya's address.

Meanwhile, two representatives of French media rights organization Reporters Without Borders (RSF) were prevented from travelling to Moscow for a press conference on the Politkovskaya affair.

"We are extremely shocked over this decision," said RSF Secretary General Jean-Francois Julliard, one of the two representatives barred, saying that they had nor received travel visas.

"Moscow does not want us to speak directly to Russians. But we're not giving up," he added.

In the RSF ranking of press freedoms in 173 countries, Russia stands near the bottom at 141. Since March 2000, 22 journalists have been murdered in Russia, according to RSF. (dpa)