WASHINGTON — Congressional Democrats said on Tuesday that they were investigating the Trump administration’s decision to lift a ban on firearm silencer sales to foreign private buyers that had been enacted to prevent the devices from being used against American troops.
Democrats are focusing in part on the involvement of Michael B. Williams, a White House lawyer who had worked for two years for a trade group representing silencer manufacturers that had lobbied to overturn the ban. The administration lifted the ban this month, paving the way for as much as $250 million a year in possible new foreign sales for companies that Mr. Williams had championed as general counsel of the American Suppressor Association.
Representative Stephen F. Lynch, Democrat of Massachusetts and chairman of the House Oversight and Reform Committee’s subcommittee on national security issues, sent a letter Tuesday to the White House budget office requesting documents related to the move, and Mr. Williams’s role in pushing it.
“The overseas sale of U.S. defense articles, especially when those weapons could endanger the safety and security of our men and women in uniform, cannot and should not be influenced by personal financial or political interests,” Mr. Lynch wrote.
The New York Times reported this month that Mr. Williams, while working as a White House lawyer, pushed to overturn the prohibition. He raised the issue with influential administration officials, creating pressure in the State Department, which enacted the ban in 2002 to protect American troops in Afghanistan and elsewhere from being ambushed.
Mr. Lynch said in his letter that his subcommittee was “disturbed” by the Times report, asserting that it “raises significant concerns about whether the safety of our men and women in uniform is being exchanged for personal or commercial profit.”
The letter is the beginning of an investigation by the subcommittee into the decision to lift the ban and potential conflicts of interest related to it, according to a Democratic committee aide.
Mr. Lynch specifically asked the White House for records of Mr. Williams’s communications related to the ban with various government officials and agencies responsible for overseeing foreign arms sales, as well as with outside groups that had been pushing to overturn the ban.
Those included the American Suppressor Association, which was started by Mr. Williams’s brother, who remains the group’s president and executive director; the National Shooting Sports Foundation; and SilencerCo, a leading maker of silencers.
The founder of SilencerCo was an inaugural board member of the suppressor association and had enlisted President Trump’s eldest son, Donald Trump Jr., to express support for making silencers easier to buy in the United States. Mr. Lynch also sought records of any communications between Mr. Williams and Donald Trump Jr., though a person close to the president’s son said he had not spoken to anyone in the administration about the matter.
Mr. Williams did not respond to a request for comment.
Silencers, or sound suppressors, attach to a firearm’s muzzle and reduce the noise made by gunfire by trapping gas released when a bullet is fired. In the United States, sales of suppressors, which are regulated by the federal authorities, have climbed in recent years. Foreign-made suppressors are widely available abroad.
Critics of the State Department’s ban on overseas sales argued that it merely hindered the ability of American manufacturers to compete. Any foreign sales from the lifting of the ban would still need to be approved by the State Department, and the suppressor association argues that such sales will not put American troops in harm’s way since suppressors do not completely silence gun shots.
Mr. Williams had worked at the suppressor association until joining Mr. Trump’s presidential campaign in 2016. When Mr. Trump took office, Mr. Williams joined the White House as an assistant deputy general counsel at the budget office and last year was named counselor and a deputy assistant to the president. It was from that perch that Mr. Williams began to press the gun issues in earnest.
His role in pushing to lift the ban fits a pattern in the Trump administration of handing over policymaking to allies of special interest groups with a stake in those policies.
Last month, Mr. Williams moved from the White House to the U.S. Agency for Global Media, as Mr. Trump shook up the leadership of the agency, raising questions about the editorial independence of the federally funded news outlets under its purview.
Mr. Williams did not stay there long, moving again this month to a top post at the Department of Housing and Urban Development.