(Adds details, background in para 2, after para 3)

MOSCOW, August 27 (RIA Novosti) - The Chechen-born leader of a Moscow organized crime group is behind the murder of Russian investigative journalist Anna Politkovskaya, Russia's prosecutor general said Monday.

Politkovskaya, known for her criticism of the Kremlin's policy in Chechnya, was gunned down in an apparent contract killing in an elevator in her apartment bloc October 7, 2006 in Moscow.

"The crime was solved over a period of 10 months. Ten people, including direct organizers, accomplices and perpetrators of the crime, have been arrested in the case," Yury Chaika said.

Chaika did not name the organizer.

Chaika said several Federal Security Service (FSB) and Interior Ministry officers have been detained in the probe into the murder.

"I have to say that, unfortunately, a former and a serving police officials and an officer from the FSB participated in [unauthorized] surveillance and intelligence gathering on Politkovskaya," he said.

"They have also been arrested," he said.