A Russian historian whose exposure of Soviet leader Josef Stalin's crimes angered state officials was cleared of child pornography charges Thursday after a long campaign by human rights activists to free him.

State prosecutors had accused Yuri Dmitriev of involving his adopted daughter, then 11, in child pornography, of illegally possessing components of a firearm, and of depravity involving a minor.

But some of Russia's leading cultural figures had said Dmitriev was framed because his focus on Stalin's crimes jarred with the Kremlin narrative that Russia must not be ashamed of its past.