Moscow (CNN) -- A suspect in the killing of Russian journalist Anna Politkovskaya in 2006 was arrested in Chechnya on Tuesday, Russia Investigative Committee told CNN.
Rustam Makhmudov was detained in Chechnya's Achkoi-Martan district, according to Russia's Interfax news agency. He will be transported to Moscow for questioning, the committee said.
The arrest was conducted by the Federal Security Service and Russia's Interior Ministry and was facilitated by law enforcement in Belgium where the suspect had been hiding earlier, the committee said.
A fierce critic of the Kremlin, Politkovskaya was found shot dead in her apartment building while she was working on a series of reports about Chechnya for Novaya Gazeta, an independent, Moscow-based newspaper.
Lawyer Murad Musayev told Interfax that videos and DNA tests will prove Makhmudov's innocence.
The slain journalist's lawyers were not impressed by the arrest.
"We do not consider the detention of the perpetrator of the crime to be a breakthrough because the investigators have long been suspecting Rustam Makhmudov of involvement in this crime. I can't thank the investigators for his arrest because it should have been done four years ago," lawyer A. Stavitskaya told Interfax.
Politkovskaya was shot dead in an elevator of her apartment bloc in Moscow on the afternoon of October 7, 2006, as she was going home.
Ibragim and Jabrail Makhmudov -- Rustam Makhmudov's brothers -- and two former law enforcement officers were suspects in the case.
A Moscow district court acquitted them in February 2009 because of lack of evidence.
The Russian Supreme Court repealed the acquittal and ordered the prosecution to re-investigate the case.
Investigators say they believe it was Rustam Makhmudov who pulled the trigger on Politkovskaya. He was on the run at the time of the killing for another crime he was charged with earlier. He has been on the international wanted list since May 2008.
CNN's Maxim Tkachenko contributed to this report.