The House’s top oversight committee officially launched its investigation into the Transportation Security Administration today with bipartisan support, citing allegations that an employee manipulated air marshals’ flight schedules and could have accessed government databases inappropriately, among other misconduct.

The House Oversight and Government Reform Committee sent a letter to Homeland Security Secretary Jeh Johnson, following a Reveal report last week that more than 60 air marshals face scrutiny as TSA investigators seek to learn to what extent national security might have been jeopardized.

The six lawmakers who signed the letter – led by committee Chairman Rep. Jason Chaffetz, R-Utah, and Rep. Elijah Cummings, D-Md., the committee’s ranking member – cited allegations included in the Reveal report: that a program specialist responsible for coordinating schedule changes, including canceled and delayed flights, gave preferred treatment to some air marshals, sometimes in return for personal favors.

The House committee also requested more information about the ongoing internal investigation into the Federal Air Marshal Service and asked for a briefing on the matter no later than March 13.

The TSA said it had no comment on the congressional investigation. In an emailed statement Friday, the agency said: “Professionalism, integrity and accountability are essential in carrying out our mission as a counterintelligence agency.”

Former air marshals told Reveal that it was common knowledge that the program specialist offered to help give better assignments. It is not yet clear how many of the air marshals now under scrutiny actually had their schedules changed or simply knew about the practice.

One air marshal, with whom the specialist had a four-year affair, had his schedule changed at least 20 times, according to the air marshal’s wife. The air marshal and program specialist acknowledged in unrelated court documents that they met around the country over the time of the relationship. Both have been placed on administrative leave.

Correction: A previous version of this story misstated Rep. Jason Chaffetz’s party. He is a Republican.

Andrew Becker is a reporter for Reveal, covering border, national and homeland security issues, as well as weapons and gun trafficking. He has focused on waste, fraud and abuse – with stories ranging from border corruption to the expanding use of drones and unmanned aerial vehicles, from the militarization of police to the intersection of politics and policy related to immigration, from terrorism to drug trafficking. Becker's reporting has appeared in The Washington Post, the Los Angeles Times, The New York Times, Newsweek/The Daily Beast and on National Public Radio and PBS/FRONTLINE, among others. He received a master's degree in journalism from UC Berkeley. Becker is based in Reveal's Emeryville, California, office.