The morass of ethical questions around Scott Pruitt’s conduct as administrator of the Environmental Protection Agency is now stunningly thick.

But the Government Accountability Office has just answered one key question amid the allegations: The EPA broke the law when it built Pruitt’s secret phone booth last year.

In an opinion published Monday, the GAO reported that the agency violated Section 710 of the 2017 Financial Services and General Government Appropriations Act. The rule states that agencies can’t spend more than $5,000 to improve the office of a presidential appointee, whether that’s new furniture, paintings, or hardware. At least, not without approval from Congress.

Pruitt’s soundproof privacy booth, which was first reported by the Washington Post in September, cost $43,238.68. And it’s illegal for another reason too, says GAO: It violates the Antideficiency Act, which states that agencies aren’t allowed to rack up bills beyond what Congress has appropriated for them.

The GAO reported that the breakdown for the bill included “$24,570 for ‘Privacy booth purchase, delivery, and assembly,’ $3,470 for ‘Concrete Floor Leveling,’ $3,360.97 for ‘Drop Ceiling Installation,’ $3,350 for ‘Prep and Wall Painting,’ $7,978 for ‘Removal of CCTV Equipment,’ and $509.71 for ‘Infrastructure Cabling and Wiring.’”

“Because EPA used its appropriations in a manner specifically prohibited by law, EPA violated the Antideficiency Act,” according to the GAO opinion.

Related Why the head of the EPA built himself a secret phone booth

The EPA has said that the phone booth was necessary for Pruitt to make and receive classified telephone calls. The agency does have authority to create and handle classified national security information, but a 2013 audit found that the agency wasn’t doing a good job of it.

The issue here, however, is that the phone booth was built without a go-ahead from the appropriators in Congress. And the EPA already has a sensitive compartmented information facility to handle classified information on a different floor of its headquarters.

The booth is part of a pattern of paranoia for Pruitt, who had his office swept for listening devices, continues to hide his schedule from the public, doesn’t allow employees into his office without an escort, and has prohibited note-taking at meetings.

The GAO opinion also represents the first clear case of Pruitt’s EPA violating the law, an uncomfortable turn for an administrator who claims to be a stickler for the law. And it probably won’t end here. There are at least half a dozen other investigations into the EPA underway, from the GAO as well as from Congress and from the EPA’s inspector general, looking into things ranging from Pruitt’s condo deal with a lobbyist to his luxury travel arrangements.

The EPA’s Office of General Counsel previously argued that Section 710 didn’t apply to the booth because it was necessary to “conduct agency business in a private space” and that it was paid for out of the agency’s environmental programs and management budget previously approved by Congress.

And in an email, EPA spokesperson Liz Bowman responded to the GAO report with this statement: “EPA is addressing GAO’s concern, with regard to Congressional notification about this expense, and will be sending Congress the necessary information this week.”