MOSCOW, September 6 (RAPSI, Yelizaveta Ponomareva) - Russian opposition activist Sergey Udaltsov wrote on his Twitter account on Wednesday that was summoned to the Investigative Committee for questioning in the Bolotnaya Square riot case.

Udaltsov’s interrogation has been scheduled for September 8.

On August 8, Udaltsov was released from prison. The activist has fully served his sentence.

Over 400 people were arrested and scores injured in the Bolotnaya Square protests that turned violent in May 2012. Dozens were later charged with inciting riots and assault on law enforcement officers.

Riot organizers Leonid Razvozzhayev and Udaltsov were sentenced to 4.5 years in prison each based partly on testimony by Konstantin Lebedev, who was sentenced to 2.5 years in prison but released on parole.

Other convicts in the riots case received punishment ranging from suspended sentences to four years in prison. Several defendants were pardoned; one is undergoing compulsory mental treatment.