Dean McKeown, who was recently banned for four years after helping to defraud punters, had his licence immediately revoked yesterday when he was adjudged to have breached the non-triers' rule at Southwell.

McKeown was given special dispensation to keep riding pending an appeal against the four-year ban. But the move backfired on the British Horseracing Authority (BHA) when McKeown was found to have made insufficient effort aboard the appropriately named Rascal In The Mix. In normal circumstances, the ban would have started immediately on account of its severity.

Having reached their conclusion, the stewards at Southwell relayed their findings to racing's central authority, which decided to act quickly. “After what has happened, we have decided to withdraw Dean McKeown's licence,” Paul Struthers, the BHA's communications director, said last night. “He will not be riding for the foreseeable future at the very least. Once he was referred today, we had to take decisive action. The BHA is acting to protect the integrity of racing.”

McKeown's four-year ban relates to his role in a corrupt agreement to stop horses winning if necessary so that accomplices could profit by laying them on exchanges. It was betting patterns that alerted the authorities to the possibility of malpractice at Southwell yesterday. BHA betting officers noted an alarming drift in the odds of Rascal In The Mix, who lengthened from 11-4 to her eventual starting price of 14-1 before finishing fifth. The officers notified the Southwell stewards before the race and this contributed to their suspicions about his ride.

McKeown left the racecourse without comment but Richard Whitaker, who trains Rascal In The Mix, found no fault with his jockey. “I am appalled at their decision,” he said. Whitaker was also referred to the BHA over the running and riding of a filly who was making her debut. Both he and McKeown can appeal the verdict of the Southwell stewards.

McKeown yesterday told those stewards that Rascal In The Mix was slowly away and resented the kickback from the racecourse's artificial surface. He claimed his mount would not have finished closer than fifth with more vigorous riding in the home straight. Whitaker told the stewards that he was satisfied with McKeown's efforts in the saddle.

Given McKeown's involvement in a conspiracy to defraud punters over a significant period, the BHA's decision to withdraw his licence is welcome and inevitable. However, the BHA has yet to send McKeown written reasons for imposing the four-year ban. The jockey is awaiting that report; he has seven days after receiving it to decide whether to appeal. Struthers said he was hopeful the report would be dispatched to McKeown later this week.

McKeown, 47, admitted last week that his career would effectively be over if he served the ban. He has also threatened to take his case to the High Court. Nevertheless, after yesterday's events, the BHA's disciplinary panel, which granted McKeown dispensation to ride pending appeal, must be ruing that decision.