Businessman Gerry Harvey has said he told mining magnate Nathan Tinkler more than a year ago to get out of the horseracing and breeding business.

Mr Harvey was calling in his debt of $40 million and selling off Mr Tinkler's Patinack Farm in the New South Wales' Hunter Valley at an unreserved auction in September.

Mr Tinkler has recently sold his rugby league team, the Newcastle Knights, and his soccer team, the Newcastle Jets, was also up for grabs.

He said he was disappointed but after the business failed to sell after 18 months on the market, he approached Mr Harvey about what he should do.

"Ultimately it had to come to a sale because I've had it for sale for 18 months and two buyers have fallen away and that was all pretty disappointing," Mr Tinkler said.

"But I feel like I've got my life on hold a little bit, with it sort of dragging its tail out there.

"I just had to make the decision.

Businessman Gerry Harvey will call in his debts and auction off Nathan Tinkler's Patinack Farm. ( ABC TV )

"I sat down with Gerry and had a chat about it all, and decided this was the best way to do it."

But Mr Harvey said he told Mr Tinkler more than a year ago he had to get out of the horseracing business.

"My view to him 14 months ago was, mate you should get out of this business - you've lost a lot of money," Mr Harvey said.

"I think he's lost over $200 million and no one ever loses that sort of money on horses and properties in such a short period of time.

"Never in Australian history has anyone lost $200 million in five or six years."

Mr Harvey said Mr Tinkler could not afford to hold onto his stake in Patinack Farm.

"He just can't afford to keep losing so he has to get out of the horse business," Mr Harvey said.

He said Mr Tinkler needed to stick to mining in order to regain his losses.

"He's realised he must get out of league and soccer and horses and concentrate on what he knows, which is mining, and hope that that generates another fortune for him or at least keeps him floating," he said.