If Frankie Dettori wins the Derby at the weekend on Authorized, the bookmakers could see a £20 million loss, the Times reports.
According to Simon Clare, director of public relations for bookmakers Coral: "It is a black-and-white situation. This is a one-horse book for everyone. If Authorized wins, we lose."
In 1997 there was a similar moment of panic among bookmakers when Entrepreneur set off at 4-6, but luckily for the bookmakers Benny The Dip was too much for Entrepreneur, who only managed fourth place.
Frankie is now odds-on favourite to win the Derby, traditionally the second most lucrative race in England behind the Grand National. On the day of the race alone, the industry is likely to take around £40 million on bets, with an estimated £30 million on the favourite this year.
Mr Clare concluded: "Frankie's massive public appeal will have a huge impact on the day and even the short price will not put many people off. If he wins, the country may celebrate but the betting industry will be the big losers."