The Transportation Security Administration (TSA) reportedly "detained" Sen. Rand Paul (R-KY) Monday morning in Nashville, Tennessee, according to a tweet sent by his communications director Moira Bagley.

"Just got a call from @senrandpaul," she wrote. "He's currently being detained by TSA in Nashville."

Aides told NBC News reporter Kelly O'Donnell an anomaly on the senator's right leg triggered an alert during a full body scan. Paul reportedly revealed that he had no metal in his leg, then refused to undergo a patdown search.

Paul has been a longtime critic of the TSA's invasive search procedures.

He told a Senate committee in June, 2011 that the TSA has "gone overboard and you're missing the boat on terrorism since you're doing these invasive searches on 6-year-old girls."

Rep. Ron Paul (R-TX) responded on Twitter about his son's incident.

"My son @SenRandPaul being detained by TSA for refusing full body pat-down after anomaly in body scanner in Nashville," he wrote.

However, in a statement to Raw Story, TSA spokesman Michael S. McCarthy disputed Paul's story.

"The passenger was not detained at any point," McCarthy said. "The passenger triggered an alarm during routine airport screening and refused to complete the screening process in order to resolve the issue."

"Passengers, as in this case, who refuse to comply with security procedures are denied access to the secure gate area. He was escorted out of the screening area by local law enforcement."

McCarthy added that Paul "has since rebooked on another flight and was rescreened without incident."

The senator returned to Washington in the afternoon, saying he would like to have a formal investigation as to whether airport scanners trigger random searches.

"We’re going to go ask them formally, but I’d love if it the media would ask the TSA head, 'Are the machines going off to give screenings?'" he told Talking Points Memo. "Because otherwise they’re not very good then if I came back through it 30-40 minutes later and the machine doesn’t go off, then my suspicion then is that maybe it is a random screening."

WATCH: Video of Paul's comments about the TSA from C-SPAN, which was published on June 22, 2011.

Ed. note: This post was updated with additional information after publication.

Photo credit: Gage Skidmore