The National Rifle Association (NRA) has acted as a “foreign asset” in providing Russian officials access to US political organizations, according to an investigation by Senate Democrats.

The results of the investigation were published by the Oregon senator Ron Wyden on Friday. The report also alleges that the NRA may have broken tax laws by using donated funds to further its officers’ business interests.

Wyden and other Democrats on the Senate finance committee found that a delegation of NRA officials traveled to Moscow in December 2015.

The trip was coordinated with Maria Butina and Alexander Torshin, who are both Russian. Butina is currently serving an 18-month prison sentence after she tried to infiltrate US conservative groups and the NRA to promote Russian political interests around the 2016 election.

While in Russia the NRA met with “a host of senior level Kremlin officials”, Wyden said. Those officials included Russia’s foreign minister, Sergei Lavrov, and the deputy prime minister, Dmitry Rogozin, who oversaw defense and munitions industries.

After the trip to Russia, the NRA allowed Butina to bring a delegation from Russia to its influential annual meeting. Wyden said the NRA also “provided access” to other conservative political organizations, including the National Prayer Breakfast and the Council for National Policy.

The investigation also found that the then vice-president of the NRA, Pete Brownell, had agreed to go on the trip in exchange for business opportunities in Russia. At least part of the trip was paid for by the NRA, according to the report. Brownell was the vice-president of the organization, which has tax-exempt status, from May 2017 to May 2018.

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“This report lays out in significant detail that the NRA lied about the 2015 delegation trip to Moscow. This was an official trip undertaken so NRA insiders could get rich – a clear violation of the principle that tax-exempt resources should not be used for personal benefit,” Wyden said in a statement.

Also on Friday The New York Times reported that Donald Trump met with the NRA chief executive Wayne LaPierre to discuss prospective gun legislation and support for the president as he faces an impeachment inquiry and potentially bruising re-election campaign. It was unclear which side initiated the meeting. The NRA contributed $30m to Trump’s 2016 campaign, more than any other outside group.

LaPierre, who has attempted to back Trump away from instituting new background check measures, told Trump to “stop the games” over gun control legislation, two people familiar with the meeting reportedly told NYT.

In response to the story, NRA released a statement denying that any quid pro quo was discussed during the meeting: “The NRA categorically denies any discussion occurred about special arrangements pertaining to the NRA’s support of the president and vice versa.”

The NRA is being investigated by the attorney general in New York, Letitia James, where the organization is chartered, over its tax-exempt status, and by the Washington DC attorney general, Karl Racine. Washington authorities are questioning whether its operations are in violation of its not-for-profit status.

“NRA officers’ apparent use of the NRA for personal gain fits a larger pattern of reported self-dealing and raises serious questions about whether the NRA broke US tax laws,” Wyden said.

Mario Koran contributed reporting