MOSCOW, January 19 (RAPSI) - The European Court of Human Rights (ECHR) has accepted an application filed by Russian opposition activist Sergei Udaltsov, who was sentenced to 4.5 years in prison for organizing the Bolotnaya Square protests in central Moscow in May 2012, his attorney Dmitry Agranovsky told RAPSI on Monday.

The application concerns Udaltsov’s detainment, his placement under house arrest and the subsequent restraint on his freedom during the inquest.

The issue of giving top priority to the complaint will be considered later, Agranovsky said.

Over 400 people were arrested and scores injured in the Bolotnaya Square protest that turned violent in May 2012. Dozens were later charged with inciting mass riots and using violence against law enforcement officers.

The case against Udaltsov and another opposition activist Leonid Razvozzhayev along with other opposition figures was initiated after the "Anatomy of Protest 2" film was shown on the NTV broadcasting network. The film claimed that the opposition was organizing a coup using funds from abroad. It showed Udaltsov and his companions allegedly talking with Georgian politician Givi Targamadze, who at the time headed Georgia's Parliamentary Defense and Security Committee, and is said to have been involved in masterminding revolutions in Georgia and Ukraine and mass riots in Belarus.

Udaltsov and Razvozzhayev were accused of organizing mass protests, convicted and sentenced in July 2014.