THE taxman is chasing almost $1 million in prizemoney from Cox Plate-winning racehorse managing owner Sean Buckley.

KEITH MOOR reports for the HERALD SUN that a court battle is looming over who should get cash won by the champion colt, Shamus Award.

Shamus Award made history last month at Moonee Valley by becoming the first maiden to win the classic Cox Plate.

And the horse ran third in the Caulfield Guineas two weeks earlier.

The Australian Taxation Office is involved in legal action to try to get from Racing Victoria $945,000 in prizemoney the colt's half owners were due from the two races.

Ultra Thoroughbred Racing, which lists Mr Buckley as its secretary and director, argues in court documents that it, not Mr Buckley personally, should get the money.

The company did so after the ATO tried to get Racing Victoria to pay it the cash to help cover the $11.5 million it claims Mr Buckley owes it in personal income tax.

A Federal Court hearing on who should get the Cox Plate and Caulfield Guineas winnings is due to start in Melbourne tomorrow.

Mr Buckley is the owner of the Ultra Tune auto service franchise.

Ultra Thoroughbred Racing's statement of claim asks that Racing Victoria pay the winnings to the court registrar and then t o whoever the court determines is entitled to it.

Documents lodged with the court reveal the ATO issued a garnishee notice to Racing Victoria "in respect of debts arising under notices of assessment issued to Mr Buckley personally".

Ultra Thoroughbred Racing has since lodged documents with the court claiming it is entitled to the prizemoney as it is the legal and beneficial owner of the cash.

The ATO recently refused a request by Ultra Thoroughbred Racing for it to withdraw its bid to get Racing Victoria to pay it the winnings.

Ultra Thoroughbred Racing's statement of claim said it bought a 50 per cent stake in Shamus Award in April 2012.

It also said that while Mr Buckley was registered as the horse's managing owner, Ultra Thoroughbred Racing was nominated as the entity to be paid any prizemoney.

Horse owner Viv Oldfield also has a stake in the colt.

In the court documents, Ultra Thoroughbred Racing claims Mr Buckley has not paid any expenses relating to Shamus Award and it, not Mr Buckley, "was entitled to 50 per cent of any winnings".

Australian Securities and Investments Commission documents list Mr Buckley as the director and secretary of Ultra Thoroughbred Racing.

Shamus Award only just made it into the Cox Plate.

It was selected as the first reserve runner after a scratching, and Racing Victoria was criticised by racing figures who felt having a maiden runner devalued the prestigious race.