The Secret Service is working to recover erased surveillance footage from the night allegedly drunk agents drove through an active bomb investigation and crashed into a White House barricade.

During a Senate Appropriations subcommittee hearing on Thursday, Secret Service Director Joseph Clancy said agency officials have contacted the manufacturer of the surveillance equipment to see if it's possible to retrieve erased footage from that night in early March, the Washington Examiner reported.

"We understand it's a concern," Clancy said. "We're doing everything we can to retrieve those images and to be as transparent as we can be."

Only a single camera angle recording was saved because of the ongoing suspicious package investigation, and all camera angles were overwritten due to agency policy, Clancy said.

The remaining footage, from the direction of E and 15th Street, showed a young woman dropping a suspicious package over the fence around 10:20 p.m. on March 4, according to Clancy.

"We don't release video to the public - because it may be evidence - in order not to taint future court hearings, we don't release it," he said.

In the event of an operational security incident, Secret Service policy is to only keep specific video footage for "investigative and protective intelligence purposes," Secret Service spokesman Robert Hoback told CNN in an email.

All other tapes are erased 72 hours after they record, Clancy told House Oversight Committee Chairman Jason Chaffetz on Tuesday.

"We inquired if there were additional tapes and angles and the director informed us that there may no be because it's their priority to erase them 72 hours after they record, which is just unfathomable," Chaffetz said. "I can't think of any good reason to do that."