Two Democratic senators have written a formal letter to the Environmental Protection Agency’s internal watchdog, asking a basic question: how many email accounts does Administrator Scott Pruitt have?

“Our offices have received information indicating that the Administrator uses three different secret epa.gov email addresses in addition to his official email address: Pruitt.Scott@epa.gov,” the senators wrote in a letter sent to the EPA’s Office of the Inspector General and first published by The Washington Post.

“It is imperative that there be an investigation into whether the agency has properly searched these email addresses for responsive documents in response to Freedom of Information Act (FOIA) requests.”

The two senators, Jeff Merkley (D-Ore.) and Tom Carper (D-Del.), say that Pruitt has “at least four” such accounts. The concern is that, when FOIA requests come into the office, the EPA may not be fully searching all the active email accounts.

Merkley has recently called for Pruitt to resign in the face of revelations of outlandish spending

According to the Post, “Pruitt’s four email addresses include one in the conventional agency format, pruitt.scott@epa.gov, as well as three others: esp7@epa.gov, adm14pruitt@epa.gov and sooners7@epa.gov, an apparent reference to the University of Oklahoma, whose football team Pruitt follows closely.”

An EPA spokesman, Jahan Wilcox, told the Post that two of the accounts are for “calendaring and public correspondence,” while a third is used “by the administrator.”

“A fourth email account was created for use by the administrator but was superseded and never used beyond three test emails,” Wilcox continued. “When we receive a FOIA request, all accounts are searched before we respond to the FOIA request.”

The EPA did not immediately respond to Ars’ request for comment.