MELBOURNE Cup fan favourite Red Cadeaux has been euthanased due to the injury sustained in last month's race.
The ABC reports the English stayer was euthanased after "irreversible complications arose" from a break in his left foreleg, sustained during this year's Melbourne Cup.
Trainer Ed Dunlop told the ABC the early stages of his recovery went well and he was "stable".
But experts at the University of Melbourne Equine Centre, where Red Cadeaux was staying said the loss of blood flow to his leg could not be fixed.
"This is my saddest day in racing," Mr Dunlop told the ABC.
"Red Cadeaux was a much loved member of our family and my thoughts are with his owner Mr [Ronnie] Arculli and my staff, particularly Robin Trevor-Jones and Steve Nicholson, who spent every day caring for this horse.
"Unfortunately the complication was irreversible and the decision to euthanise the horse, whilst terribly hard, was made in his best interests," Mr Dunlop said.
Red Cadeaux won the hearts of fans around Australia after finishing second on three occasions in the Melbourne Cup.
"Big Red" pulled up in the final straight of this year's race and later it was confirmed he had suffered a break in his foreleg.
"Red Cadeaux has given us and the racing public so much joy competing with great distinction across the world," Mr Dunlop told the ABC.
"He was an incredibly tough competitor with a wonderful nature and he will be dearly missed by all.
"On behalf of Mr Arculli and my staff, I also want to thank the Australian public and his racing fans from around the world for their wonderful support and well wishes during what has been an incredibly tough time for us all."
Red Cadeaux will be laid to rest at the site of the Melbourne Cup at Flemington Racecourse.