From left, John Roth, Rebecca Roering, Robert MacLean and Jennifer Grover are sworn in prior to testifying before the Senate Homeland Security and Governmental Affairs Committee's oversight hearing to examine the TSA’s challenges. (Cliff Owen/AP)

The inspector general for the Department of Homeland Security said Tuesday that he is investigating the leak of classified information from an undercover operation in which investigators were able to slip through airport security with weapons and phony bombs more than 95 percent of the time.

“We have started an investigation to determine where the leak was,” Inspector General John Roth told the Senate Homeland Security Committee.

The information received widespread attention in the news media and on Capitol Hill. Roth told the panel that he had briefed top officials about his findings without the information leaking to the public.

“I was as disturbed as anyone that this information got into the media,” he said.

He declined to discuss in Tuesday’s public hearing any aspect of the investigation, in which auditors from his department were able to carry weapons or bomb-like material through air­port-security checkpoints in 67 of 70 attempts this year.

“If Pre-Check is done right, it reduces the time screeners have to spend on non-risk passengers,” MacLean testified. (Cliff Owen/AP)

“What we’re doing clearly isn’t working,” said Chairman Ron Johnson (R-Wis.). “We need to think outside the box.”

Acting TSA Administrator Melvin Carraway was forced from the job last week after reports of the airport-security issues became public. U.S. Coast Guard Vice Adm. Peter Neffenger is awaiting Senate confirmation to become TSA administrator.

Asked whether security at any one airport proved to be more lax than at others, Roth said, “The results were consistent across airports.”

Former TSA head John S. Pistole said last week that some people assigned to test airport security might have had the upper hand because they were intimately familiar with checkpoint operations. He also said that unlike terrorists, intelligence-gathering networks don’t alert the TSA of their planned operations.

“The testers don’t have any special background or training in this area,” Roth said when asked whether his undercover operatives were particularly knowledgeable about overcoming security operations.

The Department of Homeland Security is investigating the leak of a classified report on airport-checkpoint failures, which concluded that TSA members failed to detect weapons and phony bombs smuggled in my undercover agents more than 95 percent of the time. (WUSA9)

The hearing came five days after the release of an inspector general report that said the TSA did not identify 73 aviation industry workers whose links to terrorism should have raised suspicion. Those workers, who had badges that gave them access to secure airport areas, were not identified in the report, and the reasons they should have been flagged were not specified.

The report said, however, that the TSA was “generally effective in identifying credential holders with links to terrorism.” It said the agency had revoked 58 airport badges since 2003 because of security concerns.

“We remain deeply concerned about [the TSA’s] ability to conduct its core mission,” Roth said.

The hearing also focused on the TSA’s Pre-Check program, one of several initiatives that speed 40 to 50 percent of passengers through airport security without the thorough scrutiny that once was common for everyone.

Fliers become eligible for Pre-Check by providing the TSA with personal information and paying a fee. Under Pistole’s direction, other passengers selected at random were allowed to use the faster Pre-Check lines.

“TSA is handing out Pre-Check [privileges] like Halloween candy in an effort to expedite passengers as quickly as possible,” testified Rebecca Roering, a TSA administrator at Minneapolis-St. Paul International Airport and a whistleblower who has revealed details of TSA operations.

She said the TSA was “well aware of the risk” in allowing passengers who have not gone through pre-screening to use the program.

Roering added, however, that the risk-based approach to security implemented by Pistole was appropriate.

“We need to focus on the passengers that really pose a risk,” she said.

Another whistleblower witness, Federal Air Marshal Robert J. MacLean, agreed.

“If Pre-Check is done right, it reduces the time screeners have to spend on non-risk passengers,” he said.

Although the TSA was not invited to participate in Tuesday’s hearing, Sen. Claire McCaskill (D-Mo.) spoke up on the agency’s behalf.

“As we all sit and pound the desk and say how bad the TSA is, we have to remember that we keep cutting their money,” McCaskill said.