A man died at Kempton Racecourse after being kicked in the head by a horse, according to a jockey.
The Surrey course was closed with two races still to run after the man in his 50s was injured in the stable yard.
The victim — believed to be a stable hand — was pronounced dead at the scene after police were called at around 9.20pm on Saturday.
A Surrey Police spokeswoman said the death was being treated as unexplained and inquiries were ongoing.
Jockey Martin Dwyer, who was riding at the fixture, told Racing UK: “Unfortunately, horses do kick out and I believe that’s what happened. They have metal shoes on and if you get a kick from a horse it can be very serious.
“Horses don’t mean to do it – if they feel frightened or threatened; if they feel someone is too close or something they do kick out but fortunately it is very rare. It is very sad.”
Trainers and top jockeys tweeted their shock as news of the man’s horror injuries emerged.
Racegoers at the Sunbury-on-Thames track were not aware until a loudspeaker announcement said that racing was to be abandoned.
Kempton’s director of racing Barney Clifford said: “Due to a serious incident in the stable yard racing has had to be abandoned.”
Reports alleged the man worked for Sussex trainer Amanda Perrett.
Nick Rust, chief executive of the British Horseracing Authority, said it was not yet able to confirm the circumstances surrounding the man’s death.
“The matter now sits with the Surrey police force and as such we are unable to provide further details regarding the individual involved and the exact nature of the incident at this time,” he said.
“I am sure that I speak for everyone at the BHA and everyone in British horseracing this morning when I state that we are truly devastated about the events which unfolded at Kempton Park last night.
“Our sympathies go to the family, friends and colleagues of the individual who has lost his life, and the entire industry will join in mourning over this tragedy.
Stalls handler Stephen Yarborough was killed at Haydock on July 21.
Yarborough died in a freak accident when he was run over as the stalls were moved. The rest of that meeting was also called off as police launched an investigation.