Race clubs have withheld almost $600,000 from Nathan Tinkler's racehorse winnings to offset his debts.

The Australian Turf Club (ATC) in Sydney had been owed almost $190,000 for months, News Ltd reported on Thursday.

Racing NSW on behalf of the ATC withheld prizemoney won by Tinkler horses at Randwick, Rosehill, Canterbury and Warwick Farm to recoup what his Patinack Farm owed for stable rent, sponsorship and other debts.

"There have been some cashflow problems and as a result we have worked towards an agreement to offset some debt," ATC chief executive Darren Pearce told News Ltd.

"Patinack Farm is very much still a valued partner of ours."

Racing NSW took the action in the past few weeks and it is believed Tinkler has already settled all amounts owing to ATC, the report said.

The Melbourne Racing Club took similar action over $400,000 Tinkler owed, News Ltd said.

Fortunately the Tinkler colt All Too Hard, a half-brother to Black Caviar, won the Caulfield Guineas, bringing his total winnings to $1.5 million.

Patinack Farm has also reportedly asked Racing Queensland to transfer prizemoney to creditors.

Meanwhile, it has emerged that Patinack Farm spent $77.5 million on 410 horses at Australian auctions since 2008, at an average price of $190,000, and last month sold 303 horses for $4.1 million - an average of $13,500.

Tinkler still owns a 1350-strong team of horses, including Group 1 champs All Too Hard and Nechita.

The 37-year-old mining tycoon has denied being on the verge of financial collapse, claiming he's the victim of "a massive media campaign to try and ruin me" over continued speculation on his money problems.

Tinkler's estimated wealth has reportedly shrunk over the past year amid rumours he has struggled to pay his bills on time, including falling behind in payments to the NSW government for rent owed on Hunter Stadium, the home ground of the Newcastle Knights and the Jets.