Sergei Udaltsov announced on Twitter that he has been told to present himself Tuesday, RIA Novosti reported.
"I got a notice in the post. The prosecutor wants to see me on Nov. 6 at 2 p.m. for an explanation, and to bring with me financial and foundation charter documents for Left Front, although we don't conduct financial activity and aren't registered with the Justice Ministry," Udaltsov told the website Gazeta.ru in a phone interview. "I intend to go, we've got nothing to hide."
He said he was given no reason for the investigation, but he said it could be the start of an effort to declare the Left Front an extremist group.
The Left Front, an alliance of several left-wing organizations, is part of chess champion Gary Kasparov's The Other Russia coalition.
Puzzle-maker slips 'Murdoch Is Evil' into Rupert Murdoch's Sunday Telegraph
Reindeer recovered after escaping from Santa during lighting ceremony