In the wake of Sept. 11, security at government office buildings is at an all-time high. But when undercover agents put security to the test at four federal buildings in Atlanta, it failed.

According to investigators with the General Accounting Office, a plainclothes agent with no building pass used a fictitious story to bypass metal detectors and X-ray screening at one federal facility. Once inside, the agent obtained access codes and building passes from security personnel.

Other agents copied the passes with commercially available computer software and used the bogus passes to gain access to three other federal buildings in Atlanta.

"They were given, in effect, they keys to the kingdom," said U.S. Rep. Bob Barr, R-Ga., vice chairman of the House Government Reform Committee, which requested the investigation last winter.

Barr presided over field hearings in Atlanta Tuesday regarding the investigation. Investigators picked Atlanta as a test city to better assess security at federal buildings outside New York and Washington, D.C.

"I’m sure Atlanta is only an indicator," said retired Lt. Col. William Cowan, a Fox News military analyst and terrorism expert. "I’m sure that federal buildings throughout the United States have the same level of security that Atlanta does."

According to investigators, a visual inspection of the counterfeit identification cards would have revealed they were missing holograms. But building security officers apparently failed to give them a close inspection.

"As long as you have people who are watching, but not paying attention or looking, but not seeing, these types of vulnerabilities will continue to be a problem," said Ron Malfi, director of the GAO’s Office of Special Investigations.

During February and March, undercover OSI agents with improper identification infiltrated the Summit Federal Building, which houses the Secret Service’s Atlanta field office; the Sam Nunn Federal Building, home to regional offices for the Environmental Protection Agency and Social Security Administration; the Martin Luther King Jr. Federal Building, which houses the Immigration and Naturalization Service’s Atlanta office; and the Richard B. Russell Federal Building, where U.S. District Court is held.

According to investigators, agents had free run of the buildings and were never questioned by anyone.

"If the most elementary effort at breaching security can succeed, I really worry that more sophisticated efforts are going on at the same time," Barr said.

Specifics of the undercover probe were discussed in a closed-door session to avoid giving terrorists any intelligence on infiltrating federal buildings. But officials who oversee federal building security promise changes.

"All the technology in the world isn’t going to do you any good if your staff isn’t there and trained to identify [a threat]," said Wendell Shingler of the Office of Federal Protective Services. "Training and getting the proper staff is definitely going to be one of our major efforts."

After Tuesday’s field hearings, Barr said he felt more confident that specific problems with federal building security had been addressed, but insisted more work needed to be done.

"I don’t have great confidence yet that we are out of the woods by any stretch of the imagination," Barr said.

Jonathan Serrie joined Fox News Channel (FNC) in April 1999 and currently serves as a correspondent based in the Atlanta bureau.