It had been hoped that the mare, successful in a record 17 races at Group One level and unbeaten in her last 24, would contest the Queen Anne Stakes at Ascot in June.

Waller says the decision to remain in Australia was made after “lengthy discussions” with the owners and jockey Hugh Bowman and “based on the best interests” of the six-year-old.

“Winx has nothing to prove to anyone, she is, and always will be, regarded as a legend of the turf and it is champions like her that make up the fabric of this great sport,” he added.

Ascot’s director of racing and communications, Nick Smith, said he wished the Winx team “the very best for the future” following their decision, adding: “It was a privilege for Royal Ascot to have been under such serious consideration for the world’s best horse.”