Pat Berdan, a consultant working with Donaghy, said he was released from Hernando County Jail in Florida, where he had been held since August after officials said he violated travel restrictions while living at a halfway house in the Tampa area.
A New York judge sentenced the ex-referee in July 2008 after Donaghy said he took thousands of dollars from a professional gambler in exchange for inside tips on games - including games he worked.
The 42-year-old pleaded guilty to conspiracy to engage in wire fraud and transmitting betting information through interstate commerce in the tips-for-payoffs scheme.
Donaghy served 13 months of a sentence that began in a federal prison in Pensacola. He was transferred to a halfway house in June and wound up in the Hernando County Jail in Brooksville after being accused of violating his probation by not showing up for work.
During his stay in prison, Donaghy wrote a tell-all book "Blowing The Whistle," that does not yet have a publisher.
Random House said last week that it had decided not to go forward with publication of the book, which in excerpts posted online includes accusations of wagering between officials working games, favoritism toward star players, and desires by the league to extend playoff series.
The NBA has said it will review the allegations that appeared on the Web site deadspin.com.
Executive Prison Consultants, a consulting agency working with Donaghy, has said the former referee plans to live in the Sarasota area and seek a job in sales or marketing.