The Federal Election Commission has begun looking into whether the National Rifle Association received illegal contributions from Russian entities during the 2016 presidential election in an effort to benefit President Trump’s campaign.

The American Democracy Fund, the liberal advocacy group that filed a complaint which triggered the preliminary inquiry, asked the FEC to investigate links between the NRA and Russian entities, including a donor with close ties to Russian President Vladimir Putin, sources told Politico. The FEC declined to confirm or deny the probe for the report because the agency is prohibited from doing so until any such inquiry is complete.