Gun Stuns Bettors at British Tracks : Horse Racing: Officials on lookout for sci-fi weapon that may have been used to disable a horse in midstride.

LONDON —  A cartoon in the Times of London showed a woman walking up to a betting window and telling the ticket seller: “Ten pounds to win on any horse that’s deaf.”

The Jockey Club doesn’t think it’s funny, and that’s why Britain’s race tracks are on the lookout for the ultrasonic stunner, a sci-fi contraption that may be capable of affecting horse races from the stands.

The Jockey Club, which oversees horse racing in the United Kingdom, told the Racecourse Assn. today to come up with ways of stopping the stun gun, detailed in a London drug conspiracy trial.

“It is recognized that there is the possibility it could upset horses during a race,” a club statement said. Anyone found with such a device at a track will be prosecuted, the club said.

The statement represented a turnaround for the club and the latest development in a week of bizarre events touching both the soul and the wallets of a nation dedicated to fair play and deeply in love with horse racing and betting on the races. Almost 10,000 Britons attend horse racing each day, and about 5,200 races are run each year, according to Jockey Club figures.

The gun, which looks like a pair of binoculars but hides a high-powered ultrasonic transmitter, allegedly was used to stun Ile de Chypre as the horse was racing toward victory in last year’s King George V Stakes at Royal Ascot.

Ile de Chypre finished ninth in the Breeders’ Cup Turf at Gulfstream Park last Saturday.

Greville Starkey, the jockey who last year was thrown from Ile de Chypre, says tests show the gun works. The Jockey Club, which initially expressed its doubts, said Starkey’s remarks made it think again.

“It seemed prudent to ask race courses to look at the ramifications of this device, despite there being no independent evidence available,” David Pipe, the club’s spokesman, said.

The club, in a statement to the nation’s 59 flat and steeplechase courses, said it still wanted to conduct its own tests to see how the gun worked.

Meanwhile, it said, security should be stepped up and plans drawn to combat the high-pitched intrusion, which witnesses have said cannot be heard by humans but sounds like a firecracker going off in a horse’s ear.

“Consequently, the stewards have asked the Racecourse Assn. to consider the security implications and to recommend any necessary additions to the Jockey Club general instructions,” the club said. “In the meantime, security arrangements remain the responsibility of racecourses after consultation with the local police.”

All of this concern stems from a drug trial involving three London area men that drew scant attention until a week ago.

James Laming, one of the defendants, testified that he developed the gun to fix races or, as it is known here, to “nobble horses.”

Describing himself as not a genius but an ingenious man, Laming testified that he invented the gun with some basic knowledge in electronics and help from the Encyclopaedia Britannica. Containing a 22-watt amplifier and miniature loudspeakers, the ultrasonic gun, which looks like the front of a jet engine, can direct a high-pitched blast directly into a horse’s ear, the court was told.

Prosecutors charge that the gun was financed by $16,000 from a cocaine distribution racket. Laming and his co-defendants admit developing the gun with the intention of fixing races but deny the drug charge.

The defendants also say they only used the gun once, on Ile de Chypre, and did not bet on that race. Laming said he was caught before he had a chance to use the gun again.