The British Jockey Club expressed disbelief this week to the damaging claim of Chris Bell of bookmaker Ladbrokes that at least one race a day in Britain is fixed.
Bell's attack on Britain's betting exchanges came in an interview with BBC2 Television's The Money Program, which is to be broadcast on June 1.
The chief executive of Ladbrokes said: "I am personally convinced by what I have read and listened to that at least a race a day, if not more, are now being corrupted by the availability of laying horses to lose on betting exchanges."
Christopher Foster, the Jockey Club's executive director, reacted: "Without seeing the program, we do not know the context in which the reported remarks were made. It could be that it was a throwaway comment, because we know of no basis on which he could make such a claim.
"Since January this year, the Jockey Club has had a memorandum of understanding with Ladbrokes and other bookmakers under which bookmakers report to our security department unusual betting patterns or any event which infers suspicious behavior.
"Consequently, if Ladbrokes had any evidence of a pattern of so-called 'fixed races', they should have shared it with the Jockey Club. They have not done so."
Others in the British racing world saw Bell's comments as part of the intense battle between bookmakers and betting exchanges, where individuals can back or lay a horse. British bookmakers are pressing the government strongly for more regulation of betting exchanges and calling for them to be taxed at a higher rate.
Rupert Arnold of the British National Trainers' Federation said: "Chris Bell's remark to the BBC about race fixing is the second damaging allegation made by a senior representative of a major bookmaker in recent weeks. Several questions spring to mind. What evidence does Mr Bell have to back up this statement and has he passed that on to the Jockey Club's security department?
"Why would bookmakers seek to undermine the reputation of racing in such a dramatic way? It is suggested that their strategy is related to their turf war with betting exchanges. If so, it is a mighty dangerous game to be playing with the reputation of a large industry on which thousands of honest, hard working people depend for a livelihood."
John Blake, chief executive of the British Jockeys' Association, reacted: "These sensationalist headlines give the impression that the sport is being corrupted on a day-to-day basis, which along with the Jockey Club, we would strongly refute."
Alan Ross, managing director of Ladbrokes UK, supported his colleague's comments and pointed to evidence produced by Clive Reams of Racefax last year.
Reams, whose company monitors betting exchanges, told the Jockey Club in November of 171 races over 12-month period he alleged had suspicious betting patterns.
Ross argued: "The integrity of British racing is being undermined by betting exchanges which allow unlicensed, anonymous layers to lay horses to lose.
"All bookmakers in the High Street have to be licensed and have a permit. It is in the interests of the racing industry to keep the sport as clean as possible."