Washington (CNN) Scott Pruitt's unprecedented 24/7 security detail began at his own request and on his first day as Environmental Protection Agency administrator, according to a letter from the agency's inspector general, contradicting his claim the around-the-clock protection was a response to an assessment of death threats against him.

Pruitt "requested 24/7 protection once he was confirmed as Administrator," EPA Inspector General Arthur Elkins wrote in a letter on Monday.

Pruitt and EPA have defended his security procedures -- including first-class airplane seats and a heavily beefed-up team of special agents costing at least $2 million last year -- as necessary because of the threat review.

"These are threats that the IG has documented," Pruitt told lawmakers at a hearing last month, after reading from a document. "We can provide this to you."

"According to EPA's assistant inspector general, Scott Pruitt has faced an unprecedented amount of death threats against him and his family," the agency said in a statement last month . "Americans should all agree that members of the President's Cabinet should be kept safe from these violent threats."

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