The Transportation Security Administration is looking into the March 29 stop of an official with the Ron Paul organization while he passed through St. Louis.

Steve Bierfeldt, development director for the Campaign for Liberty, told the Washington Times that he was singled out for additional screening at Lambert-St. Louis International Airport. The screeners quizzed him about a metal box that contained more than $4,700 in cash and checks following a regional conference in St. Louis.

During the stop - which Bierfeldt recorded on his iPhone - a TSA employee and members of the St. Louis Airport Police Department could be heard asking him why he had so much money, whether it was his money and why he was in St. Louis. The Times reported in its Monday article that the money was received from ticket sales, bumper stickers, books and other conference-related materials.

Bierfeldt repeatedly asked the officers whether he was required by law to answer some of the questions, according to the recorded exchange.

Officers threatened to turn him over to the FBI or the Drug Enforcement Agency.

During the exchange, two of the officers grew testy.

“You want to play smartass, and I’m not going to play your f—ing game,” one officer, believed to be a TSA screener, is heard saying.

“Are you from this planet? I mean do you understand the question that I’m asking you? Why can’t you answer the question?” another officer asked.

“You’re acting like a child,” one of the officers said.

Bierfeldt was allowed to go and made it to the gate in time to board his flight to Washington, D.C., the Times article stated.

The TSA said in a statement that the metal box was picked by by an X-ray machine and because the box contained a large amount of cash and other items, it was deemed “more appropriate” to continue screening in a private area. But the agency added that the “tone and language used by the TSA employee was inappropriate.”

“TSA holds its employees to the highest professional standards,” the agency said in a statement. “TSA will continue to investigate this matter and take appropriate action.”

The agency said movements of large amounts of cash through the checkpoint “may be investigated by law enforcement authorities if criminal activity is suspected” and that “passengers are required to cooperate with the screening process.”

Bierfeldt told the Times he didn’t believe he was legally required to answer the screening officer’s questions and that “carrying cash is not a crime.”

He added: “It is a dangerous precedent if the government can order you to tell them where you get your money, and no law requires them to know where I work or where I spend my free time and where I go on vacation.”

Bill Switzer, the TSA’s federal security director in St. Louis, referred the Post-Dispatch to an agency spokeswoman.

Lambert Police Chief Paul Mason said today that he has reviewed the incident and listened to the tape, and said his officer’s interview skills “could have been better.” In fact, the department is using the case to improve interview and communication techniques.

Mason said that when one of his sergeants arrived on the scene, he asked Bierfeldt if he worked for the Paul campaign. When Bierfeldt said, “Yes,” the sergeant told him he was free to go.