House Democrats are calling for an investigation into reports that Environmental Protection Agency chief Scott Pruitt is spending almost $25,000 to build a protective, soundproof booth to guard against eavesdropping.

"The reported installation of this equipment is unprecedented and may represent yet another example of bureaucratic malfeasance by the Trump administration," wrote Rep. Frank Pallone of New Jersey, the top Democrat on the Energy and Commerce Committee, in a letter sent Thursday to EPA Inspector General Arthur Elkins, Jr.

Reps. Paul Tonko, D-N.Y., and Diana DeGette, D-Colo., also signed the letter.

The Washington Post recently reported that Pruitt is spending nearly $25,000 to build the soundproof enclosure in his office, citing the vendor that was contracted to install the device.

"The installation of a dedicated communications booth in the administrator's office raises questions regarding why such equipment is needed and what types of conversations Administrator Pruitt is having that would warrant a private soundproof booth," the letter read.

If it is found that the booth is meant to ensure privacy, then it is the "latest action in a troubling pattern of secrecy and distrust" at the EPA under Pruitt, according to the letter. It pointed out that there has been a pattern of prohibitions on EPA staff meant to limit the use of cell phones or take notes in meetings with the EPA chief.

The Democrats want Elkins to establish why Pruitt needs the soundproof booth in the first place, and pointed out that the EPA headquarters is already equipped with a similar booth. At a minimum, spending money on an unnecessary device or upgrade could represent a violation of policies and agency rules meant to stop "waste, fraud and abuse," the letter read.

They want Elkins to also probe whether EPA's current policies are adequate to prevent such waste, if indeed EPA is building the booth.