WASHINGTON (Reuters) - Two high-level Environmental Protection Agency employees whose names have come up in investigations of Administrator Scott Pruitt’s ethics and travel have resigned from the agency, the EPA confirmed on Tuesday.

Pasquale “Nino” Perrotta, a former Secret Service agent who served as the head of Pruitt’s security team, resigned on Monday but said he will continue to cooperate in a U.S. House of Representatives investigation of his role in costly decisions around Pruitt’s security. ABC News first reported the resignation on Tuesday.

Albert “Kell” Kelly, who ran the agency’s Superfund cleanup program, also announced his resignation, the EPA confirmed. Kelly, a friend of Pruitt’s from his days in Oklahoma, was barred by the Federal Deposit Insurance Corporation from working at any U.S. financial institution after unspecified violations while working at a bank in that state.

Lawmakers last week grilled Pruitt in back-to-back hearings on reports of ethics violations, excessive spending on travel and security, close industry ties and the reassignment of agency whistleblowers who flagged concerns about high spending.

Those issues included the installation of a $43,000 soundproof phone booth in Pruitt’s office and routine use of first-class flights - both of which the EPA has argued were important to Pruitt’s safety and privacy.

Perrotta had also hired a business associate from a firm where he also works to carry out a $3,000 security sweep of Pruitt’s office, which internal staff said did not meet national security standards.

Pruitt praised both men for their work at EPA, citing Kelly’s “tremendous impact on EPA’s Superfund program” and Perrotta’s service to four EPA administrators.

House Oversight Committee Chairman Trey Gowdy said on Sunday on CBS’ “Face the Nation” that his committee had scheduled interviews with Perrotta and other senior Pruitt aides this week.

A committee aide told Reuters the staff will conduct a transcribed interview with Perrotta on Wednesday and that his resignation will not affect his appearance before the panel. The committee also is confirming dates for transcribed interviews with other EPA witnesses, the aide said.

The panel received more than 1,000 pages of documents it requested from the EPA in February and April related to Pruitt and his staff’s use of first-class flights and a condo rental agreement between Pruitt and the wife of an industry lobbyist.

President Donald Trump has not indicated whether the investigations would affect Pruitt’s tenure.

“At this point, EPA is complying with our requests,” the aide said.

Several Republicans in the House who have embraced Pruitt’s deregulatory agenda said Pruitt was unfairly grilled by Democrats, but others said his answers to some key questions were vague.

U.S. Representative Frank Pallone, the top Democrat on the House energy and commerce committee, said despite the resignations of some of Pruitt’s controversial associates, his colleagues will not ease up on the scrutiny.

“Democrats will continue to shine light onto the corruption at Scott Pruitt’s EPA, even if congressional Republicans refuse to join us,” he said.