Russian rights activist Valentin Gefter announced Monday he was resigning from a presidential human rights council, bringing the total number of resignations to 15 since late last year.
"I can no longer remain under the control of officials … who do not respect the norms established by law and elementary morals in their relationships with free citizens," he was quoted by Russia's state-run news service RIA Novosti as saying.
The presidential human rights council has no legal authority. Several high-profile members resigned following State Duma elections in December. The ruling United Russia party maintained its dominant position in elections widely viewed as fraudulent.
Opposition voices in Russia have grown louder since December. Mass protests erupted when Vladimir Putin won a third non-consecutive term as president early this year.
Political analyst Dmitry Oreshkin announced his resignation after the Putin re-election, describing the former prime minister as "an illegitimate president."
Oreshkin drafted a report that said 14 percent of the ballots in the March presidential election were stuffed in favor Putin.