At Tuesday's hearing, the chairman of the Subcommittee on Transportation Security asked US transportation authorities whether it was true that airports did not check the criminal history of their workers after they had passed initial background checks.

MOSCOW, February 4 (Sputnik) — US airports do not check the criminal history of their employees, the FBI's Deputy Assistant Director of Counterterrorism Gary Perdue confirmed Wednesday.

At Tuesday's hearing, the chairman of the Subcommittee on Transportation Security, John Katko, asked US transportation authorities whether it was true that airports did not check the criminal history of their workers after they had passed initial background checks.

"That is correct from my knowledge," Perdue said, as quoted by the CNN.

The announcement came a day after a CNN investigation revealed that most US airports allow employees access to airplanes and the tarmac without security screenings. Investigation showed that only two major airports in the country, namely Miami International Airport and Orlando International Airport, make their employees pass through metal detectors.

During the hearing, members of the Subcommittee criticized existing loopholes in airport security and discussed ways to reduce potential insider threats posed by employees. The head of the Transportation Security Administration Mark Hatfield, however, said that physical screening of all airport employees was "cost prohibitive."

The hearing came after a gun smuggling scheme in Atlanta airport was revealed in December last year. A Delta Air Lines employee used his security clearance to help a former Delta worker to bring firearms in his hand luggage. The two men managed to smuggle 129 handguns and two assault rifles onto planes between May and December 2014.