– An assessment of threats aimed at Scott Pruitt, the administrator of the Environmental Protection Agency, conducted by the agency's Homeland Security office in February, undercuts claims made by Pruitt's security team to try to justify millions of dollars in security expenditures, said an internal document obtained by a Senate Democrat.

Sen. Sheldon Whitehouse, D-R.I., wrote on Tuesday to Sen. John Barrasso, R-Wyo., chairman of the Senate Committee on Environment and Public Works, that the EPA's Homeland Security Intelligence Team reviewed an earlier memo in February and found no specific credible threats to Pruitt. The earlier memo, from October, was created by Pruitt's protective security detail, led by Pasquale "Nino" Perrotta. It was used to try to justify much of Pruitt's large security detail and first-class travel.

The same February assessment described repeated efforts by EPA intelligence officials to tell the agency's inspector general and senior leadership "that 'the threat' to the Administrator was being inappropriately mischaracterized" by Pruitt's security detail, Whitehouse wrote in the letter, sent jointly with Sen. Tom Carper, D-Del.

"It is hard to reconcile the public statements of E.P.A., and the President, with these internal and external assessments," Whitehouse and Carper wrote. They acknowledged that the materials may be incomplete.

But, they added, "Another view is that certain factions within E.P.A. have justified the exorbitant taxpayer spending incurred by the Administrator's first-class travel and large entourage of security personnel through unsubstantiated claims about threats to his security, either at the direction of the Administrator himself or others in the agency."

The EPA acknowledged Tuesday that the agency official who had signed off on the assessment questioning Pruitt's security threats had been dismissed. The dismissal of Mario Caraballo, deputy associate administrator of the EPA's Office of Homeland Security, was unrelated to this issue, said Donna Vizian, a principal deputy assistant administrator at the EPA.

According to two people familiar with the circumstances, Caraballo had been under investigation related to his military service. One said that the investigation had been resolved more than a year ago.

Whitehouse and Carper called the timing of his dismissal "deeply troubling."

The Associated Press reported last week that Pruitt has spent about $3 million on security, a figure confirmed by the New York Times. An EPA spokesman, Jahan Wilcox, said, "Scott Pruitt has faced an unprecedented amount of death threats against him."

Pruitt has been under fire for reports that he rented a condominium for $50 a night from the wife of a lobbyist with business before his agency, spent at least $120,000 in taxpayer-funded first-class travel, and retaliated against staff members who questioned his spending and the need for a security force more than three times the size of past administrators'.