Embattled EPA Administrator Scott Pruitt told a Senate hearing on Wednesday he did not recall ever asking his security detail to use lights and sirens in government vehicles. However, seconds later, a U.S. senator submitted evidence that the Trump deputy had in fact made the request.

Claims that Pruitt had asked security personnel to flash lights and blare sirens to speed up trips to the airport or dinner surfaced earlier this year in a New York Times report on alleged workplace retaliation at the EPA. The allegations were leveled by the former head of Pruitt's security detail, Eric Weese, who was reportedly moved to another position after refusing to sign off on first-class travel for Pruitt.

Democratic Sen. Tom Udall of New Mexico asked Pruitt whether he had personally asked his security detail to use sirens and lights, which is usually reserved for the president.

"I don't recall that happening, Ranking Member Udall," Pruitt said. "There are policies that the agency follows, the agents follow, and to my knowledge they followed it in all instances."

Udall once again claimed Pruitt personally requested sirens and lights on a number of trips. Pruitt responded, "No, I don't recall that."

Udall then submitted an internal EPA email contradicting that claim to the Senate subcommittee on Interior, Environment and Related Agencies. In the email titled "Lights and Sirens," the former head of Pruitt's security detail, Pasquale Perrotta, told several EPA staffers, "Btw - Administrator encourages the use ..."

The email was attached to a letter sent to EPA Inspector General Arthur Elkins, who is conducting several investigations into Pruitt's conduct. The letter, sent by two Senate Democrats on Wednesday, asked Elkins to investigate Perrotta's tenure as head of Pruitt's security detail.

"Mr. Perrotta appears to have been the individual that Administrator Pruitt transmitted most or all of his security demands to, and appears to have obliged the Administrator's demands to spend exorbitantly on unjustified security measures," Sens. Thomas Carper (D.-Del.) and Sheldon Whitehouse (D-R.I.) wrote.

Perrotta is one of several EPA staffers who recently resigned amid a flurry of allegations of impropriety leveled against Pruitt.

The cost of Pruitt's security is just one of about a dozen issues being probed by Congress, the White House and other government officials. Pruitt's rental of a Washington apartment linked to an energy lobbyist, his frequent first-class travel, and several other issues are also under investigation.