Sen. Ron Wyden has questions for the National Rifle Association.

The Oregon Democrat requested any documents showing financial links between the organization and Russia, The Associated Press reported Friday.

Wyden’s request comes after reports last month that the gun lobbying titan may have received money from a top Russian central bank official during the 2016 presidential election.

The FBI is investigating any ties the NRA might have to Alexander Torshin, the deputy governor of Russia’s central bank and a close associate of President Vladimir Putin, a number of outlets reported last month.

“The national security as well as legal implications of these reports make it imperative that Congress conduct a thorough investigation,” Wyden wrote in a letter to Treasury Department Secretary Steven Mnuchin in which he requested the documents.

Wyden also sent a letter to NRA treasurer Wilson Phillips Jr. asking for any documents that could show financial transactions between the group and Russians.

Wyden is “specifically troubled by the possibility that Russian-backed shell companies or intermediaries may have circumvented laws designed to prohibit foreign meddling in our elections,” he wrote to Phillips.

Wyden sits on the Senate Intelligence Committee, which is investigating Russia’s coordinated effort to influence the 2016 U.S. elections as well as possible collusion between Russia and President Donald Trump’s 2016 campaign team.

The probe is one of three separate congressional inquiries into Russian meddling in U.S. elections.

The NRA poured cash into efforts to support Trump’s candidacy in 2016 after the president took a pro-gun stance on the campaign trail.

Torshin, the Russian central banker, is a lifetime member of the NRA.

Democratic lawmakers and security experts worry that the president and Republican-controlled Congress have not done enough to deter Russia from re-upping its 2016 influence campaign for the 2018 midterms.

CIA Director Mike Pompeo indicated this week that the matter is under control.

The former Kansas congressman is confident that “America will be able to have a free and fair election [and] that we will push back in a way that is sufficiently robust,” he told the BBC on Monday.

The impact of Russian activity on the 2018 midterms “won’t be great,” Pompeo said.