Jockey Eddie Ahern has lost an appeal against his 10-year ban for "conspiring to commit a corrupt or fraudulent practice".
The 35-year-old was punished in May following an investigation by the British Horseracing Authority.
Ahern was found guilty of breaking anti-corruption rules in five of his races between September 2010 and March 2011.
Before his suspension, the Irishman had been used by a number of top trainers, including the late Sir Henry Cecil.