HONOLULU -- Officials have opened a federal investigation after a woman found a Transportation Security Agency uniform at the Salvation Army thrift store in Kailua.

Nurse Mary Ellen Zigli was shopping for hospital scrubs on July 3 at the Salvation Army store when she spotted a shirt among the racks. She said she immediately knew it should not be there.

"It was a white collared shirt and it had a TSA logo patch on the sleeve and a TSA gold shield patch that was on the chest part, and it had embroidery on the back that had TSA right under the collar," Zigli said.

Zigli did not buy the shirt being sold for $2.50, but she wrote a letter to the Homeland Security office and Salvation Army about her concerns.

"My concern was that someone would get a hold of that and use it to do some harm at the airport," she said.

The Salvation Army confirmed that it had the shirt and that workers immediately removed it from the racks and destroyed it. The organization said it has a policy of not accepting or selling any type of donated uniform.

"You know with all the 6,000 to 8,000 pieces of clothing that's hung each day that's the thing. One slipped through. One shirt slipped through, and yes, it was one too many, but that's the first one we've had," Salvation Army Maj. Julie Beauchamp said.

TSA also has a strict policy on employee uniforms that includes withholding paychecks until the uniforms are returned to the company. An agency spokesman said security at the airport would not be breached even with a shirt being released to the public.

"They're not getting into our operation just by the shirt they're wearing. They need identification, they need a four-digit code, they need a digitized ID card, all requirements to get into secure areas of the airport," TSA spokesman Nico Melendez said.

The local TSA office said there is an ongoing investigation into the case.