Masked police raid Moscow offices of oil tycoon's group

Masked police on Thursday raided the Moscow offices of a civil society organization funded by former oil tycoon Mikhail Khodorkovsky.

Police said they suspected the group, Open Russia, was preparing banners, leaflets and posters that contained calls for "extremist activity" and planned to distribute them at an opposition protest on Sunday.

Khodorkovsky said the official reason for the raid was fiction because Open Russia was not planning to participate in Sunday's protest, which in any case was recently canceled. The real motive, he said in a statement posted on his website, was a film his organization is making about Chechen leader Ramzan Kadyrov's "place in the current government system."

With personal support from President Vladimir Putin and generous Kremlin subsidies, Kadyrov has ruled Chechnya like a personal fiefdom and used his feared security forces to track down and kill foes. Increasingly, he has tried to stake out a greater national role, to the consternation of some even within the government.

Open Russia posted photographs on Twitter of the raid, including some showing police checking office computers.

Khodorkovsky noted that the raid took place during Putin's nationally televised call-in show, during which he said he welcomed opposition participation in elections.

Khodorkovsky spent 10 years in prison on charges widely seen as punishment for challenging Putin's power. Since his release in late 2013, Khodorkovsky has become a strong opposition voice from exile in Switzerland.