The Supreme Court today annulled the 2-and-a-year sentence for Ildar Dadin and closed his case.
Dadin was convicted in December 2015 of breaking strict new legislation regulating public demonstrations that Russia passed in 2014. The law increased the penalties for those detained repeatedly at unsanctioned protests.
Human rights groups have described Dadin as a political prisoner who was only involved in nonviolent protests.
Last fall, Dadin said he was tortured by prison guards who carried out group beatings and threatened to rape and murder him. He later was transferred to another prison.