Victorian jockey Damien Oliver has been dumped from Cox Plate second favourite Green Moon on a day of controversy and sensation that has clouded Melbourne's spring carnival.
Owner Lloyd Williams replaced Oliver with Craig Williams, who sacked himself from the favourite, Pierro.
In a switch that has added to questions surrounding the beaten Caulfield Guineas favourite, Williams claimed the Green Moon ride on a day when newspapers reported Oliver bet A$10,000 on a rival horse in a race in which he was riding.
The other horse, Miss Octopussy, won the race run at Moonee Valley in October 2010.
The allegation, aired in Fairfax newspapers yesterday, stems from police inquiries into race fixing that have so far implicated several jockeys, including the recently disqualified Danny Nikolic.
Oliver has denied the allegations, calling them "damaging and hurtful".
"I have been a jockey for 24 years," Oliver said in a statement. "My record and reputation show me to be honest, committed and trustworthy."
The race in question is also being investigated by racing stewards who have declined to comment. Green Moon's owner Lloyd Williams had only announced Oliver as Green Moon's rider on Saturday.
Less than 24 hours later he announced in an SMS that Oliver was off the horse and that he was open to offers. Soon afterwards he named the new rider.
The riding change has cast doubts over the immediate future of Pierro, whose eight-win streak ended.
His trainer, Gai Waterhouse, gave an assurance after the Guineas that Pierro would still run in Saturday week's Cox Plate, but a change of heart wouldn't surprise as his defeat by All Too Hard is analysed.
Williams' defection also means Waterhouse must now find two jockeys light enough to ride Pierro and stablemate Proisir, who both have 49.5kg in the Cox Plate.
French galloper Shahwardi scored his first win in three years and chalked up another Melbourne Cup tick for the foreign horses.
The 7-year-old was declared a Cup chance by rider Kerrin McEvoy after he steered him from last to first in the Herbert Power Stakes (2400m).
Shahwardi is trained by Alain De Royer-Dupre, who won the Melbourne Cup with Americain in 2010.
The win has further strengthened the foreign raiders' claims on spring's two glamour features with the Caulfield Cup still on the radar for the gelding.
Stable spokesman Joe Murray said he was impressed by Shahwardi's performance after his relatively recent arrival in Australia.
"It was a great run," he said. "The trainer has prepared him beautifully.
"He's only been here a few weeks and to perform like that is amazing. Tony [Bloom] who is the owner, really wants to aim for the Melbourne Cup."
Murray said he was "not sure" whether the Caulfield Cup option for Shahwardi would be taken up.
McEvoy was upbeat about Shahwardi's prospects. "There was a bit of action early, a bit of pace, and that was the plan, to ride him to be last off the bridle, and he enjoyed it. Obviously it's a step up in grade but he's travelled over well and he'd be some chance in the Melbourne Cup."
Shahwardi ($15) won by a length from Excluded ($7) with Exceptionally ($7.50) third.