OKLAHOMA: Airport security agents got a surprise on Tuesday when a woman in a wheelchair approached a checkpoint in Oklahoma City, took off her trench coat and was wearing only a black lace bra and panties.

Airport officials said that police were called over, questioned the woman, Tammy Banovac, a 52-year-old retired surgeon, and allowed her to proceed to security.

She was given an "enhanced" pat-down because she was in a wheelchair. During screening of her carry-on and laptop an alarm for nitrates was triggered, the Transportation Safety Administration said in a statement on Wednesday. The TSA said she was not allowed to proceed to her Southwest Airlines flight to Phoenix.

Authorities said nitrates could legitimately be present in medication, or if someone was hunting recently and there were traces of nitrates from the bullets.

A video of the underwearclad Banovac, wearing a pearl necklace and holding a dog in her lap, was shot by a passerby and posted on YouTube.

Banovac later said that she chose the more than halfnaked approach because she had previously had an unpleasant "hands-on" experience at the airport.

She said though she has always been hand-searched because she uses a wheelchair , she felt violated due to the pat-downs that have recently been employed. "If it happened anywhere else, it would have been sexual assault ," Banovac said.