Melbourne - Three-time Melbourne Cup runner-up Red Cadeaux has been euthanised following injuries the gelding received in this year's race, Victoria Racing said on Saturday.
The English 10-year-old, trained by Ed Dunlop, failed to finish in Australia's biggest race at Flemington on November 3 after fracturing his left fore fetlock.
Initial fears about Red Cadeaux's welfare appeared to have been allayed following immediate veterinary treatment and surgery.
But it was announced on Saturday that because of a loss of blood flow to Red Cadeaux's foot on the left foreleg and no prospect of correcting the issue, the decision was made to put down the chestnut galloper.
The horse's final resting place will be at Melbourne's Flemington Racecourse, following a request from owner Ronnie Arculli, Victoria Racing said.
"This is my saddest day in racing. Red Cadeaux was a much-loved member of our family and my thoughts are with his owner Mr. Arculli and my staff, who spent every day caring for this horse," Dunlop said in a statement.
"Unfortunately the complication was irreversible and the decision to euthanise the horse, whilst terribly hard, was made in his best interests.
"Red Cadeaux has given us and the racing public so much joy competing with great distinction across the world. He was an incredibly tough competitor with a wonderful nature and he will be dearly missed by all."
Red Cadeaux endeared himself to Australian racing fans with second placings in the Melbourne Cup in 2011, 2013 and last year, having come within a whisker of claiming the prize four years ago when nosed out by Dunaden.
Michelle Payne made history as the first female jockey to win Australia's 154-year-old Melbourne Cup when she rode 100-1 outsider Prince of Penzance to a shock win earlier this month.