Manduro has won at the highest level over a mile and 10 furlongs

The five-year-old, the highest rated racehorse in the world, won his last five races and was second favourite for next month's Prix de l'Arc de Triomphe.

French trainer Andre Fabre said the horse's ability over trips ranging from a mile to 12 furlongs set him apart.

"Manduro was the best horse I have trained, and the best by a good margin," said Fabre.

Manduro sustained a serious leg injury when winning at Longchamp.

The injury, a fractured bone in a hind leg, is not thought to be life-threatening, but has ended his racing career.

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BBC racing presenter Clare Balding said: "He was one of the most impressive horses this season and for me, the horse of the year so far.

"I was really looking forward to seeing him take on the Derby winner Authorized in the Arc."

Authorized, the mount of Frankie Dettori, is now rated 6-4 favourite to land the Arc on 7 October.