Legal experts say it's likely special counsel Robert Mueller secretly gained access to the National Rifle Association's (NRA) tax returns as part of the investigation into Russian meddling in the 2016 election, according to a McClatchy report.

Mueller's team is reportedly looking into NRA donors with links to Russia and investigating whether some donors used the organization to illegally funnel foreign money to President Trump's campaign.

The NRA spent $30 million in support of Trump's campaign in the 2016 presidential race.

NRA officials maintain that the organization has not been contacted by the FBI, but legal experts told McClatchy that it would be "routine" for investigators to access the group's tax filings through the IRS.

The tax filings would reveal the NRA's "dark money" donors, whose names are hidden on public documents.

David F. Axelrod, an Ohio lawyer who formerly prosecuted cases for the Justice Department's Tax Division, told McClatchy that prosecutors often request tax filings "entirely in the background, with no notice to the subject of the investigation."

Former senior Justice Department official Michael Zeldin told McClatchy that "it would be basic blocking and tackling for the prosecutors to seek all relevant tax returns."

Mueller's office declined to comment for McClatchy's report.

The NRA disclosed in April that it received about $2,500 in contributions from 23 Russia-linked individuals since 2015. McClatchy reported earlier this year that the FBI was looking into whether one of those donors, Alexander Torshin, used the NRA to funnel money to the Trump campaign.

Torshin is a Russian politician and deputy of the country's central bank.

He has ties to former NRA President David Keene and hosted him for a pro-gun conference in Russia.

Torshin has previously claimed that his connections to the NRA have given him access to the president.

NRA general counsel John Frazer said in the April disclosure that Torshin has not made additional contributions beyond his dues as a member of the organization, but later said that the NRA was "reviewing our responsibilities with respect to him" after he was hit with sanctions from the Treasury Department.

The Hill has reached out to the NRA for comment.