Washington ? At least 16 people later linked to terror plots passed through U.S. airports undetected by federal officials who were on duty to spot suspicious behavior, according to a government report.

The airport-based officials were part of a federal behavior detection program designed to spot potential terrorists and others who pose a threat to aviation. The program, started in 2003, is one of 20 layers built into the nation’s aviation security system.

The Government Accountability Office questioned the scientific basis of the entire program in a report released Thursday. The program is dubbed SPOT — Screening Passengers by Observation Techniques. It was instituted by the Transportation Security Administration “without first validating the scientific basis for identifying passengers in an airport environment,” the GAO said.

“A scientific consensus does not exist on whether behavior detection principles can be reliably used for counterterrorism purposes,” the congressional auditors said.

The public version of the GAO report did not include the names of the 16 terror suspects who eluded detection. But among the 16 who slipped past the behavior detection officials at Newark Liberty International Airport, the report said, was an individual who “in August 2008 later pleaded guilty to providing material support to al-Qaida.”

Both Najibullah Zazi, the Denver-area shuttle driver who led the plot to blow up the New York City subway system, and an accomplice, Zarein Ahmedzay, pleaded guilty to providing material support to al-Qaida. Federal investigators said both men also traveled through the Newark airport in August 2008.

“TSA has bungled the development and deployment of a potentially important layer of aviation security,” said Rep. John Mica, R-Fla., who requested the report. Mica, the top Republican on the House Transportation and Infrastructure Committee, called on the Obama administration to reorganize the TSA so it can better carry out its mission.

Earlier this week, President Barack Obama announced his intention to nominate the current deputy director of the FBI to lead the TSA. Two previous nominees dropped out after concerns were raised about their backgrounds.

Between May 2004 and August 2008, behavior detection officers who work for the TSA have made about 1,100 arrests, but none were for terrorism, the GAO said. TSA spokesman Greg Soule said behavior detection officers at Orlando International Airport spotted a person in April 2008 who was carrying components and instructions for a pipe bomb in his luggage.

Soule said the SPOT program “is designed to look for passengers displaying behaviors that indicate they are trying to avoid detection.”

The agency did not agree with all the GAO’s findings.

“TSA strongly believes that behavior detection is a vital layer in its aviation security strategy. … Leaders within the community of behavior detection researchers agree,” Jerald Levine, the director of the Homeland Security Department’s GAO liaison office, said in a response included in the report.