The Transportation Security Administration is under fire over the way they handled the 17-year-old niece of a U.S. congressman who was subjected to a pat-down while traveling.

Channel 2's Scott MacFarlane learned the incident has now triggered a federal investigation.

The girl is the niece of Rep. Ralph Hall of Texas.

Hall said his niece was traveling with classmates from Southwest Christian School in Texas to Australia when the incident happened.

The 17-year-old girl was wearing a sundress and was pulled aside for a pat-down screening.

TSA documents said 'during the pat-down of her stomach area" her sundress slipped revealing her breasts in public.

Surveillance cameras caught the incident on video. An internal TSA investigation found the incident was 'embarrassing' and 'unfortunate,' but also accidental.

Hall and a colleague have now called for a federal probe of the case.

The incident happened two years ago, but MacFarlane just now was able obtain the records through the Freedom of Information Act.

MacFarlane also found U.S. air passengers filed 17,000 complaints with TSA about enhanced pat-downs since 2009.

Georgia Sen. Saxby Chambliss, wrote the TSA to review, "rigorous, potentially invasive screenings at Hartsfield -Jackson."

Sharon Cissna, a breast cancer survivor with a double mastectomy, told MacFarlane the TSA insisted on patting down her prosthetics.

"We are being touched inappropriately, yet this is the law," Cissna said.

Rich Roth is an aviation security consultant who defends TSA's decision to pull young girls aside for pat downs, saying terrorists will use anyone to cause an attack.

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"Can the TSA just stop screening 17-year-old girls?" MacFarlane asked Roth.

"See, they can't. If they did it'd be just as bad," Roth said. "They have no problem using kids. Anytime you say, 'This is going to be a group we're not going to screen,' that's what they're going to look for."

Hall told MacFarlane he wanted the officer who disrobed his niece fired.

The TSA said it apologized and gave the officer more training. In a statement TSA said it regrets the incident that caused embarrassment to the young lady.