Long has been using a staff driver from his department to drive him to and from North Carolina in an official vehicle since he first took over as head of FEMA a year ago. He is now overseeing the preparations for Hurricane Florence, which is expected to hit the Southeast hard.
Long is driven seven days a week and 24 hours a day - so any of his movements are in government vehicles.
"I would never intentionally run a program incorrectly", he said.
Long also said in a Thursday press briefing that he "would never intentionally run a program incorrectly" and meant to cooperate with the investigation.
FEMA Administrator Brock Long speaks during a news conference at the National Hurricane Center as National Hurricane Center Director Ken Graham, right, looks on, Wednesday, May 30, 2018, in Miami.
Presidential emergency alert system text coming next week
Donald Trump may be texting your cell phone next week and it won't be to send a political message or bash his adversaries. At about the same time on September 20, FEMA will also run a test of the Emergency Alert System on television and radio.
CNN reached out to the DHS IG for comment and is awaiting a response.
Long reportedly began having a government driver take him home since he took control of FEMA previous year. "At this time, we are fully focused on preparing for, responding to, and recovering from Hurricane Florence and the storms in the Pacific", DHS press secretary Tyler Houlton told Politico in a statement. "If we made mistakes with the way a program was run, then we'll work with OIG to get this corrected".
During a Thursday briefing on Hurricane Florence, Long denied any wrongdoing to reporters and acknowledged an ongoing investigation from the DHS inspector general.
"Doing something unethical is not part of my DNA and it's not part of my track record in my whole entire career", said Long, who leads the Federal Emergency Management Agency.
Politico, citing three people familiar with the situation, reports that Long used the cars during commutes from his home in North Carolina to Washington and the Department of Homeland Security's inspector general report is now looking into whether or not taxpayer funds had footed Long's bill for travel. The administrator's trips home to North Carolina have also drawn the ire of his boss, DHS secretary Kirstjen Nielsen, who reportedly confronted him about them this summer.