Godolphin's European horse of the year in 2000 died on Sunday night at the age of five.

A spokesman for breeder Sheikh Mohammed confirmed: "Dubai Millennium became uncomfortable on Sunday and it was evident that a third emergency surgery was necessary."

"But it soon became clear that there were complications of the intestinal tract that were inoperable.

"His prospects were hopeless and on humane grounds Dubai Millennium was not allowed to recover from the anaesthetic.

"The horse was the most marvellous patient and everyone who knew him is very sad to see him go."

Dubai Millennium was ridden by Frankie Dettori in his first nine races with American Jerry Bailey deputising for the injured Italian at Royal Ascot in what turned out to be his last race.

And Dettori was shocked to learn of his death.

The jockey said: "I'm absolutely devastated - it's a tragedy. He was one of the best horses I've ridden."

With Dettori on board, the horse had indeed proved himself a world-beater over 10 furlongs last year.

He ran away with the 2000 Dubai World Cup - a race Sheikh Mohammed reportedly had in mind when changing the horse's name from Yaazer when taking him from David Loder's gallops at Newmarket.

And he put up a breathtaking display to land the Group One Prince Of Wales's Stakes at Royal Ascot by no less than eight lengths.

But just as a match with French champion Montjeu was being planned last August, Dubai Millennium fractured a leg on the gallops and had to be retired.

He went to stud the winner of nine career races and �2.75m in prize money.

He will be buried in the stallion graveyard at Sheikh Mohammed's Dalham Hall Stud - where he was foaled and also stood as a stallion.