Kieren Fallon had an appeal against his license being revoked because of race-fixing charges rejected on Friday, barring the six-time champion jockey from riding in Britain.
The Horseracing Regulatory Authority (HRA) also rejected appeals by jockeys Fergal Lynch and Darren Williams and barred them from riding in Britain until the result of any trials. The trials are not expected to start until July next year.
"I am obviously devastated by the HRA decision," Fallon said in a statement.
"I always thought that a man was innocent until proved guilty. I cannot understand this decision as I am confident that I have done nothing wrong, and my lawyers are confident that the case against me has no validity whatsoever," he said.
The jockeys were among 11 people charged on Monday in "Operation Crypton," Britain's biggest race-fixing investigation. They are accused of conspiring to defraud customers of online betting exchange Betfair. Their licenses were revoked on Monday due to the charges.
Fallon denies any wrongdoing. He can continue to ride in Ireland, but believes his "career is in ruins" because of the decision.
"My livelihood is dependent upon racing and I will be appealing against this decision as it is extremely harsh and inconsistent given the HRA panel's verdict on Alan Berry published earlier this week," he said.
Trainer Berry was cleared to continue working by the HRA on Tuesday, despite also being charged by police in the investigation.
All three jockeys will appeal the decision to a separate HRA panel in the next two weeks, with the option of taking their case to court should they lose.
Ireland's Fallon, one of horse racing's most successful jockeys, won his second Irish Derby in a row last Sunday, riding 9-2 favorite Dylan Thomas to victory at the Curragh.
Nicknamed "the punter's pal," Fallon's successes on the track and his actions off it have made him one of racing's fan favorites. He became a champion jockey for the first time in 1997, going on to win the Epsom Derby in 1999, 2003, and 2004. He also won the 2003 Breeder's Cup in the US.