The British Horseracing Authority has blocked Darren Williams' application for a new riding licence.
The jockey is due to complete a three-month riding suspension for his part in a race-fixing inquiry after he admitted to passing information for reward when facing a disciplinary panel in June.
However, the governing body has refused to allow Williams to resume race-riding, without giving details at this stage.
BHA Media Relations manager Paul Struthers said: "We received Darren Williams' licence application on September 18, ahead of his period of disqualification ending on September 25.
"In line with standard practice, any rider returning from a period of disqualification must meet with the Licensing Committee in consideration of his application.
"In this case, we have informed Mr Williams that we will be objecting to his licence application.
"However, until he has received the full reasons for our opposition in writing, it would be inappropriate to publicly discuss these reasons.
"The ultimate decision is one for the Licensing Committee and the date that has been provisionally set for the hearing is October 21."
Williams said he was devastated by the news, saying he will lose eveything if he is unable to ride again.
"If they didn't want me to ride, why didn't they say this three months ago," he told the Racing Post. "I could have got on with my life. But riding is all I know. What else can I do.
"I am shocked and gutted and just can't believe it. I'm going to lose my house, my car, everything."

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