The U.S. Transportation Security Administration is denying allegations that an airport screener seized a toddler's cup and mistreated his mother, taking the unusual step of posting security camera footage on its Web site.

At issue is whether Monica Emmerson, a former Secret Service officer, was improperly detained June 11 after she spilled water out of her child's cup at Washington's Reagan National Airport.

TSA has banned most fluids at airport security checkpoints for nearly a year because of concern about possible liquid explosives.

A TSA report said Emmerson told an officer she was a Secret Service agent, flashed her credentials and said she was exempt from the "stupid" policy restricting liquids on planes.

The story quickly spread on the Internet after blogger Bill Adler, a Washington author, saw a note Emmerson wrote on a Web site for city parents and interviewed her. He wrote that a TSA screener seized the cup after asking if there was water in it, causing Emmerson's son to cry. Emmerson was told she would have to leave the security checkpoint and dump out the water if she wanted to keep the cup.

As she left the security line, Emmerson "accidentally spilled" the water, she and Adler wrote.

TSA, however, said Emmerson dumped, not spilled, the water on the floor.

Emmerson declined to comment to The Associated Press.

The video that TSA posted on its Web site Friday shows Emmerson being escorted from the security checkpoint as she appears to take the top off the sippy cup and shake it upside down.

It shows that after she was confronted by several officers, she used paper towels fetched by the TSA to clean up the spot as other passengers stream by her.

The TSA said in a statement that the incident and the videotape demonstrate that its "officers display professionalism and concern for all passengers."