Senate Democrats wrapped up an 18-month investigation on Friday into the National Rifle Association and its interactions with Maria Butina and other Russians, concluding that the organization’s top officials were aware that Russia was using its connections to the NRA to improve its access to American lawmakers. They also found that, contrary to an NRA spokeswoman’s insistence that her organization’s leaders were not acting in an official capacity, the NRA itself had sanctioned and supported a 2015 trip by its leaders to Moscow.

In the report, titled “The NRA & Russia: How a Tax Exempt Organization Became a Foreign Asset,” Democrats on the Senate Finance Committee made the argument that the NRA’s leadership, in giving Russian operatives access to American legislators in exchange for personal business opportunities, had violated the nonprofit’s tax-exempt status.

The majority of the complaint deals with Maria Butina and Alexander Torshin, who, according to the Justice Department, used the NRA to access other conservative organizations on behalf of the Russian government. Butina, who worked under Torshin, pleaded guilty in December to conspiring to act as a foreign agent and is now serving an 18-month sentence in federal prison. Torshin, a senior official at the Russian central bank, has been sanctioned by the U.S. The Justice Department had already said that Butina and Torshin had tried to infiltrate a “gun rights organization,” but Friday’s report expanded on the NRA’s role in connecting the Russians to American politicians.

Committee Democrats, led by Sen. Ron Wyden, relied on the NRA’s own internal documents but was limited by the unwillingness of Republicans on the committee to participate and his inability to force certain NRA officials to turn over documents or answer the committee’s questions.

The report focused on a 2015 visit by some NRA leaders to Moscow. Butina, with the help of her then-boyfriend, the Republican operative Paul Erickson, arranged for former NRA President David Keene to attend the Moscow trip, where Keene had hoped to meet Russian President Vladimir Putin, according to previous reports. The Senate report noted that Butina had hinted the same possibility of meeting Putin to Peter Brownell, the incoming president of the NRA.

“Russia believes that high level contacts with the NRA might be the BEST means of neutral introduction to either the next American President OR to a meaningful re-set in relations with the Congress under a (God forbid) President Clinton,” Erickson wrote in an email to Brownell. “This simple good will trip would have enormous diplomatic consequences for a future U.S. / Russia bilateral relationship to the world.”

But the trip was only one in a series of meetings between NRA leadership and Russian operatives and officials, and the report detailed deeper connections between the group and the Russians than had been previously reported. One month before that meeting, according to the report, then–NRA President Allan Cors—under the recommendation of Keene—went hunting with Sergey Kislyak, who was the Russian ambassador to the U.S. at the time and later became a focus of the Mueller investigation and was in contact with several people in Donald Trump’s orbit. In an email to Keene about the idea, Cors wrote that he “would welcome any opportunity engage the ambassador with the NRA.” Before the hunt occurred, Kislyak also met with Cors and Keene at the NRA headquarters. Cors, the report said, “welcomed” Kislyak’s “influence campaign.”

According to the report, NRA officials connected Butina and Torshin to members of Congress and groups such as the National Prayer Breakfast and the Council for National Policy. The NRA footed the costs for Torshin and Butina to attend third-party events where they expanded and deepened their connections to conservative American politics.

The report also alleged that the NRA officials were motivated by their own potential financial gain. Brownell, the chief executive of a firearms accessories company, was told the 2015 Russian trip could allow him to meet with Russian firearms companies that might prove good for business. He joined the trip, and his lawyer later admitted that Brownell had been planning to look into business opportunities there. Keene and his wife also reportedly helped organize the trip because of business opportunities in Russia.

The committee found evidence that the 2015 trip was in part paid for by the NRA and that the NRA later tried to cover up payments related to the trip. This, Wyden said, points to an abuse of the NRA’s nonprofit status. “This report lays out in significant detail that the NRA lied about the 2015 delegation trip to Moscow,” Wyden said in a statement. “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.

“The totality of evidence uncovered during my investigation, as well as the mounting evidence of rampant self-dealing, indicate the NRA may have violated tax laws,” he said.

Tax-exempt organizations are not allowed to use their funds for the financial gain of any of their officials. Friday’s report refocuses attention on the question of the NRA’s tax-exempt status—something that is already being scrutinized by attorneys general in New York and D.C.

Republicans on the committee, however, have argued that any wrongdoing mentioned in the report would be too small to warrant a change to the NRA’s status, and they have said the report exaggerated some of its claims about the ties to Russian operatives.