Jordan said there were no problems with the track surface

The horse suffered multiple fractures to the lower part of one of its legs while warming up for a gallop.

"It's the worst kind of thing that can happen," said Newmarket-based Elsworth. "It's upsetting and it's like losing a friend or a member of the family."

The 24-strong field for Australia's top race will be named at the weekend.

Elsworth has trained a number of high-profile horses over the jumps and on the Flat, including Desert Orchid and Persian Punch.

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"The horse was in a lot of pain, the right decision was to put the horse down," said Racing Victoria director of racing operations Leigh Jordan.

Jordan said the injuries appeared to be a pure accident, and there was no problem with the surface, moistened by rain after a recent dry spell.

"It had a great grass cover," he said.

"There are local horses galloping there as there normally are. There's no problem with the track condition. It's just one of those things that happen."

It was a sad end for the team associated with Wunderwood, who Jordan estimated had spent 150,000 Australian dollars (�60,000) in their quest to win the Cup.

"They've come a long way from overseas. They've spent a lot of money to come here to run in a Melbourne Cup so it's pretty disappointing," he said.