VIOLATION: Erin Chase says she was forced to leave her child and subject herself to a hands-on screening by a female officer from the Transportation Security Administration.

A prominent "mommy blogger" has described in humiliating detail how she was violated by a US airport security official who touched her genitals while executing the controversial new "enhanced pat-down" procedure.

Her account of the incident, which she retold in excruciating detail in a blog post, has become another cause celebre in what many Americans see as a mounting catalogue of violations of their civil liberties.

Erin Chase, a blogger and author who has become a minor celebrity though her book on frugal recipes, The $5 Dinner Mom Cookbook, was screened at Dayton International Airport, Ohio, last Friday.

She was forced to leave her child in the pram and subject herself to a hands-on screening by a female officer from the Transportation Security Administration, the US federal organisation that is responsible for airport security.

"She felt along my waistline, moved behind me, then proceeded to feel both of my buttocks. She reached from behind in the middle of my buttocks towards my vagina area.

"She did not tell me that she was going to touch my buttocks, or reach forward to my vagina area.

"She then moved in front of me and touched the top and underneath portions of both of my breasts.

"She did not tell me that she was going to touch my breasts.

"She then felt around my waist. She then moved to the bottoms of my legs.

"She then felt my inner thighs and my vagina area, touching both of my labia.

"She did not tell me that she was going to touch my vagina area or my labia."

Chase said she was left stunned after the examination, which she likened to being sexually assaulted.

"I stood there holding my baby in shock. I did not move for almost a minute," she wrote.

"I stood there, an American citizen, a mom travelling with a baby with special needs formula, sexually assaulted by a government official. I began shaking and felt completely violated, abused and assaulted by the TSA agent. I shook for several hours, and woke up the next day shaking."

It comes as a US passenger who refused a body scan and pat-down search at a San Diego airport has become an internet sensation following his stance.

John Tyner posted a mobile phone audio recording of his encounter at Lindbergh Field on Saturday.

The software engineer couldn't board a flight after refusing a full-body scan that reveals an image of what's under his clothes. He also wouldn't allow a Transportation Security Administration worker to conduct a groin check.

Mr Tyner told the worker: "If you touch my junk, I'm gonna have you arrested."

Mr Tyner's blog says he left the airport - but only after being threatened with a lawsuit and fine for failing to complete security screening.

The new security measures are part of a number of changes to airport security procedures that were rushed in after a foiled plot by Nigerian man Umar Farouk Abdulmutallab who tried to detonate explosives hidden in his underwear aboard a US flight from Amsterdam to Detroit.

Chase said she was motivated to tell her story because she did not want to remain a silent victim of excesses of government authority. She said she had spoken to TSA management at the airport and to Dayton police.

"I intend to request the TSA to arrange for counselling services to be provided to me, so I can deal with the aftermath of the sexual assault that took place," she wrote.

Her story follows the case of John Tyner, a software engineer who posted audio and video recordings of his run-in with the TSA at San Diego airport.

Tyner refused a full-body scan, a procedure that reveals an image of what's under a passenger's clothes. He also wouldn't allow a TSA screener to conduct a groin check.

A public backlash against the new security measures includes a call to boycott body scans next Wednesday, one of the busiest travel days, the day before Thanksgiving.

- with agencies