WASHINGTON — The $2.50 fee collected from airline passengers for each leg of their flights may not be ending up where it's supposed to — at the government agency in charge of airline security.

The Homeland Security Department's inspector general, Richard Skinner, said in a report yesterday that airlines are underpaying the Transportation Security Administration an estimated $14.5 million every year in passenger security fees.

The fees were imposed after Sept. 11, when the TSA was created to take over responsibility for airline security.

"TSA needs to provide closer oversight of the air carriers to ensure proper collection (of the fees)," the report said.

The agency said it will make sure the airlines are audited to ensure they pay what is owed.