The Nathan Tinkler-owned Caulfield Guineas winner All Too Hard has been sold to Vinery Stud, the under-siege mining magnate's thoroughbred operation has confirmed.

The sale of the colt, a half-brother to racing superstar Black Caviar with the potential to generate millions of dollars in stud fees, comes as Tinkler's business empire crumbles.

Patinack Farm spokesman Troy Palmer described the sale as a "win-win" for for Vinery and Tinkler's thoroughbred venture.

"While it is disappointing to sell All Too Hard, we have retained an opportunity for him to service some of our mares and naturally, the more success he enjoys on the track and in breeding, the further he will enhance the reputation of his sire, Patinack's Casino Prince," Palmer said.

Vinery Stud general manager Peter Orton said a deal to buy All Too Hard had been tabled well before the colt won the Group One Caulfield Guineas in October.

"We have been negotiating this deal for the past six months as we always believed All Too Hard was one of the most exciting stallion prospects we have seen for many years," Orton said.