American jockey Frank Hayes may hold the record for the most unique horse racing win in history.

Back in 1923, the jockey won the only race of his career on board 20/1 shot Sweet Kiss at New York's Belmont Park.

However, it became apparent after the race that Hayes had actually died on board the horse during the race.

Reports say track doctor John Voorhees ran over to examine Hayes but pronounced him dead 'immediately' after suffering a mid-race heart attack.

Somehow the sportsman, who was between 23 and 35 due to a lack of official records, had managed to stay on the horse while crossing the finishing line.

On June 4, 1923, jockey Frank Hayes won Belmont Park's steeplechase on the horse, Sweet Kiss, after suffering a fatal heart attack during the race.

As well as Hayes, it is also said Sweet Kiss never raced again - earning the nickname 'Sweet Kiss of Death'.

According to Keeneland Library, Sweet Kiss won a total of $1775 in earnings during his career.

"The grim reaper paid a sensational visit to the Belmont Park track yesterday," wrote the Brooklyn Daily Eagle one day after the bizarre race.

Portrait of jockey Frank Hayes from the New York Daily News, June 7, 1923

"The exertion and excitement proved too great," added the New York's Daily News in the days after.

Hayes was described as "well-liked and a favourite in the saddling room and stable and took a great pride in his calling."

The jockey remains the only man in history to win a race while dead.

"Despite his sudden death, Hayes somehow remained in the saddle long enough for the 20-1 long shot to jump the final fence and cross the finish line in first place," said the Guinness Book of World Records.

Horses and exercise riders train during a morning workout at Belmont Park , New York.

Almost 100 years later, it is still not clear how Hayes actually died.

Many suggest his heart failure was brought about after losing significant weight to slim down to 130lb.

"He was confronted with the task of taking off nearly 10 pounds in 24 hours," the Buffalo Morning Express wrote.

"This morning he spent several hours on the road, jogging off surplus weight. He strove and sweated and denied himself water and when he climbed into the saddle at post time he was weak and tired."