Tim Donaghy, the ex-NBA referee who served time in a federal prison camp for betting on basketball games, got called for a traveling violation Monday - and it cost him a trip to the county prison.

The Delaware County native, who has been living at a Tampa, Fla., halfway house since he was released from the prison camp in mid-June, thought it was perfectly OK to visit a local health club Friday, according to his lawyer.

The feds thought otherwise, and decided Monday morning to toss him into the Orient Road Jail for the unauthorized trip.

The Federal Bureau of Prisons will now decide whether to return him to the halfway house or send him back to the prison camp.

"He was supposed to be at work but wasn't there, he was somewhere else," said Ron Lindbak, spokesman for the U.S. Marshals Service, which took Donaghy into custody.

Lindbak could not provide additional details yesterday on what led to Donaghy's rearrest, but said he failed to comply with federal rules.

"They don't mess around. The halfway houses have pretty strict rules," Lindbak said. "Pretty much any violation is going to get you sent back to jail."

Donaghy's attorney, John Lauro, called the incident a "misunderstanding." He said Donaghy, 42, went to the nearby health club to work on his knee. Donaghy has said he sustained the knee injury in November at the Pensacola prison camp when he was attacked by a man claiming to have New York mob ties.

Lauro said his client thought he had permission to leave the halfway house and advised his case manager's office, but federal authorities "felt that he hadn't gone through the proper channels," Lauro said.

Lauro said he was optimistic that Donaghy's sentence would be completed in October regardless.

"We're just hoping that the misunderstanding can be cleared up," Lauro said.

Assistant U.S. Attorney Jeffrey Goldberg, who prosecuted the case, declined to comment yesterday.

Donaghy was sentenced last summer to 15 months in prison on wire fraud and interstate gambling charges. The Villanova grad dished inside NBA information to two old classmates from Cardinal O'Hara High, setting off a scandal that roiled the league for more than a year.

The disgraced ref is also working on a tell-all memoir about his 13 years in the NBA. It will examine what Donaghy calls a "culture of manipulation and fraud" within the league, and offer advice to gambling addicts.