Dual Derby winner Australia has been retired to stud, said a Coolmore representative.

In a shock announcement, time has been called on the racing career of the high-class Galileo colt, who had been set to make his swan song on British Champions Day at Ascot next Saturday.

Kevin Buckley, UK representative for Coolmore, told Channel 4 Racing: "Unfortunately Australia developed a problem in his right-hind hoof during the week.

"Following consultation between the resident farrier at Ballydoyle, our vet, John Halley, and the respective owners, the decision was made yesterday to retire him to Coolmore."