US federal prosecutors in Washington have arrested a 29-year-old woman with links to the National Rifle Association and accused her of acting as a covert agent inside the US on behalf of a senior Kremlin official, just hours after US President Donald Trump and Russian President Vladimir Putin met in Helsinki.

The announcement of the arrest of pro-gun activist Maria Butina comes just days after special counsel Robert Mueller charged 12 Russian intelligence officials with directing a sprawling hacking effort aimed at swaying the 2016 election.

Ms Butina is a Russian gun rights advocate who founded a pro-gun organisation, the Right to Bear Arms, in that country in 2011.

She has been involved in coordinating in recent years between American gun rights activists and their Russian counterparts, US media accounts have reported.

Ms Butina, a Russian national who has been living the US, was charged with conspiracy to act as an unregistered agent of the Russian Government and accused of working to infiltrate American political organisations, including the National Rifle Association.

The charge was brought by the US Attorney for the District of Columbia and do not appear to stem from Mr Mueller's investigation.

Court papers shows part of the criminal complaint against Maria Butina. ( AP: Jon Elswick. )

According to court papers, Ms Butina met with US politicians and candidates, attended events sponsored by special interest groups — including two National Prayer Breakfast events — and organised Russian-American "friendship and dialogue" dinners in Washington with the goal of "reporting back to Moscow" what she had learned.

Court papers do not name the Kremlin official.

The person is described as a member of the Russian legislature who later became a top official in the country's central bank.

Prosecutors also note that the official has since been sanctioned by the US.

Ms Butina hosted several leading NRA executives and pro-gun conservatives at her group's annual meeting in 2015, according to the reports in The New York Times, Time and the Daily Beast.

Among those who attended were former NRA president David Keene, conservative political operative Paul Erickson and former Milwaukee County Sheriff David Clarke, later a strong Trump supporter.

AP