The State Duma on Thursday turned down investigators' request to revoke immunity from a Communist deputy accused of striking police officers at an opposition event.
"Study of the relevant materials has shown that only the prosecutor general can make such a recommendation," Duma Speaker Sergei Naryshkin told reporters, Interfax reported.
Top investigator Alexander Bastrykin had signed the request.
Investigators are seeking to open a criminal case against Communist Deputy Vladimir Bessonov, who they suspect of fighting with police at an unsanctioned opposition gathering on Dec. 2 in Rostov-on-Don. Members of both houses of parliament, the State Duma and Federation Council, have immunity from prosecution.
Bessonov, who organized the 100-strong gathering, earlier denied his guilt in an interview with Izvestia.
"There was a scuffle there, but I personally didn't touch anyone. I didn't even try to — why would I?" he said.
Bessonov said in the interview that the event wasn't a protest, as authorities claimed, but a meeting with voters and that police officers had stormed the event prior to the scuffle.