At least 73 people who are employed in the airline industry and are linked to terrorism-related activity codes made it past the Transportation Security Administration (TSA) without notice, according to a report released by the inspector general's office of the Department of Homeland Security.

These employees worked for airlines, airport vendors and other airport-related employers, and they all made it through TSA's security clearance even though they were on watch lists, the report found.

"TSA did not identify these individuals through its vetting operations because it is not authorized to receive all terrorism-related categories under current interagency watchlisting policy," the IG report says.

In addition, TSA let the airlines and airports where these people were employed do their own background checks.

"TSA relied on airports to gather complete and accurate information from the credential applicants," the IG explained.