Threats against EPA head Scott Pruitt prompt additional security The EPA administrator has recently had his office swept for listening devices.

 -- Environmental Protection Agency administrator Scott Pruitt recently had his office swept for listening devices and installed biometric locks on his office doors, the latest steps to increase security to combat what agency staff says are "unprecedented amount of threats."

The agency paid an outside firm $3,000 to sweep the administrator's office for "covert/illegal surveillance devices" in March, according to documents first reported by the Associated Press and shared with ABC News by an EPA source. The Associated Press also reported that the EPA spent almost $6,000 to install biometric locks on the administrator's office.

“Administrator Pruitt has received an unprecedented amount of threats against him...there is nothing nefarious about security decisions made by EPA’s Protective Service Detail," agency spokesman Jahan Wilcox said in a statement.

He also said that former Administrator Lisa Jackson who served President Barack Obama also had a similar security sweep.

"It's not unreasonable to get your office swept if you have a job like his job," ABC News law enforcement consultant Brad Garrett said Thursday.

The EPA has a law enforcement office that employs federal agents that conduct criminal investigations and protect the administrator. The Inspector General's Office, which also investigates threats against EPA employees, said it has opened more cases than in the previous year and that more of them have been threats directed at the administrator.

EPA Assistant Inspector General for Investigations Patrick Sullivan told the Washington Post that 32 percent of threats investigated this year were directed at the administrator, including "some very personal, ugly threats," compared to 9 percent of threats that were directed at former administrator Gina McCarthy in 2016.

Pruitt's round-the-clock security has also been more expensive than previous administrators, according to documents obtained by E&E News through a FOIA request. Those documents showed that Pruitt's security detail cost more than $830,000 during his first three months in office, compared to about $465,000 for McCarthy and $423,000 for Jackson during the same time periods.

Michael Hubbard, a former law enforcement official with EPA, said that past administrators have also received threats, but that he couldn't remember the same level of security in his 20 years at EPA.

"While it's not exorbitant it's a total waste of a number of thousands of dollars while you're cutting back the services of this agency," he said Thursday.

Hubbard, who retired four years ago, said that increased spending on this kind of security while cutting other parts of the budget shows that the agency isn't prioritizing its mission to protect health and the environment.

Some of Pruitt's security-related spending has already been under scrutiny, with the EPA inspector general recently announcing he will look into whether Pruitt misused any appropriated funds when he had so-called “privacy booths” with secure phone lines installed in his office earlier this year. The EPA has called the booth a "SCIF", a Sensitive Compartmented Information Facility, and said Pruitt needs the secure line to make calls about classified information and communicate with the president.