Transportation Security Administration officials said a report accuses Vitter of activating an alarm by opening a security door in an attempt to board a United Airlines flight, The Washington Post said Friday.
Vitter's alleged attempt to enter a jet bridge on March 5 is considered a Class 1 misdemeanor under airport security regulations.
Vitter has admitted in a statement he inadvertently went through a wrong door at a Dulles gate, but has dismissed a report of a bitter run-in with an airline employee.
Meanwhile, National Republican Senatorial Committee spokesman Brian Walsh defended the Louisiana Republican by pointing out how the media approached a similar airport incident involving U.S. Sen. Charles E. Schumer, D-N.Y.
"There's a clear double standard here on how this story is being covered versus Senator Schumer using his office to have a US Airways plane leaving LaGuardia early," he told the Post, referring to Schumer's alleged use of his position to get a LaGuardia Airport shuttle to leave New York ahead of schedule.