A Moscow city court on Wednesday closed a case against Sergei Udaltsov who was detained at an opposition rally two weeks ago.
Police said Udaltsov ignored their demands to leave the venue and attempted to stage an unsanctioned march on a nearby boulevard, obstructing traffic.
The Meshchansky District Court ruled that Udaltsov had done no wrong.
His lawyer, Violetta Volkova, said the video presented by the police showed that her client was detained before the authorized rally officially ended while the march did not take place.
Event organizers said about 100,000 people showed up for the rally on Sakharov Ave. September 15, the latest in a string of anti-Kremlin protests ongoing in the Russian capital since December.