Trained by Aidan O'Brien, the four-year-old fell short of his best form this season, winning just one of his three starts. Camelot was being trained for the Breeders' Cup Turf next month but was found to be lame yesterday.
Unbeaten as a two-year-old, including a Group One win in the Racing Post Trophy, Camelot excelled at three.
Victory in the 2000 Guineas at Newmarket was followed by a smooth display in the Derby at Epsom before he had to show his courage to win the Irish equivalent.
The son of Montjeu then attempted to become the first horse since Nijinsky to win the Triple Crown but had to settle for a three-quarter-length second to Encke in the St Leger before finishing down the field in the Prix de l'Arc de Triomphe. After that race he was struck down with a bad bout of colic and, while he returned with a Group Three win at the Curragh this season, he finished behind Al Kazeem in the Tattersalls Gold Cup and the Prince of Wales's Stakes at Royal Ascot and did not run again.
"From the very first time we saw him at the sales we just loved him," said trainer O'Brien. "He was the perfect racehorse, a beautiful horse with a terrific action. Speed, class and a super-intelligent horse to go with it - he had it all. Unfortunately we never saw the same brilliance on the racecourse as we had done before his colic operation, but he was showing signs of it at home in recent weeks so it's obviously disappointing that he won't get the opportunity to run again." Camelot will stand at Coolmore next season, with his fee yet to be announced.
Meanwhile, Cirrus Des Aigles is one of 15 horses still in contention for the Qipco Champion Stakes at Ascot on Saturday. Winner of the race in 2011 and second to the brilliant Frankel 12 months ago, Corine Barande-Barbe's pride and joy looked right back to his best when winning the Prix Dollar at Longchamp last time.
The seven-year-old will be a hot favourite to regain his Champion Stakes crown, especially with the forecast rain set to supply him with his favoured soft ground.