MOSCOW, October 19 - RAPSI. On Thursday, the Basmanny District Court in Moscow issued an arrest warrant for opposition activist Sergei Udaltsov's assistant Konstantin Lebedev on suspicion of planning mass riots, a court spokesperson told RAPSI.

Both Sergei Udaltsov and his assistant were questioned on Wednesday. Investigators are also searching for the third suspect, Leonid Razvozzhayev, an assistant to parliamentarian Ilya Ponomarev.

Udaltsov has been released on bail and Lebedev was detained for 48 hours.

The court granted the petition of the investigation and concluded Lebedev should be arrested for two months.

In turn, the investigator noted that if Lebedev is convicted, he may face four to ten years in prison.

The Investigative Committee took a close look into the suspects' activities after the "Anatomy of Protest-2" documentary was broadcast by NTV.

The filmmakers claim that the opposition has been preparing a coup using funds and militants from abroad. The film shows Udaltsov and his companions talking with the then Georgian parliament's defense and security committee head Givi Targamadze, who is said to be experienced in planning "color" revolutions in Georgia and Ukraine, as well as mass riots in Belarus.

The investigation into the film has established that the voice in the scenes filmed by a hidden camera was Udaltsov's and that the meeting shown in the film took place in Minsk in late June 2012.