Kauto Star put down after a fall in the paddock
Kauto Star - the gelding who won races and racegoers' hearts - has been put down after falling in the paddock and suffering severe neck and pelvis injuries.
The British eventer Laura Collett announced his death on Twitter.
The 15-year-old had been retired from racing in 2012 and Laura Collett had successfully retrained him in dressage.
Kauto Star and Laura gave a dressage display at the Barbury Horse Trials last year. And in March they appeared together in publicity for Channel 4's Cheltenham Festival coverage - along with Denman, Big Bucks and Masterminded.
Kauto Star won the Cheltenham Gold Cup twice. He won 23 of his 41 races, including five King George VI Steeplechases.
Kauto Star's owner, Clive Smith told BBC Radio 5 live: "It is really devastating - he was looking fit and well at Laura Collett's yard. The main injury was to the neck, as it gets worse it attacks the spinal cord. He also fractured his pelvic bone. A really sad time indeed."
"He had a great talent for never giving up. He wanted to win. With jockey Ruby Walsh riding him, he put this massive effort in at the end of races. He had a heart of a lion."