New Zealand's latest star Catalyst will remain with Clayton Chipperfield despite Australian trainers circling after his 2000 Guineas win.

Catalyst scored his fifth win from six starts in Saturday's Group One Guineas (1600m) at Riccarton and with an Australian autumn campaign next for the three-year-old, speculation was rampant he would be transferred.

Rick Williams, general manager of owner Dick Karreman's Oaks Stud, said the intention was for Chipperfield to retain Catalyst.

Williams has been full of praise for Chipperfield and the way he has managed Catalyst despite the former leading jumps jockey's relative inexperience as a trainer.

"He has been in this game for 20-odd years," Williams told NZ Racing Desk.

"He is 39-years-old. He's a very experienced horseman.

"It is no surprise to me that if you give him a good horse he can do the job.

"My preference will be to leave him with Clayton. Dick and I haven't discussed it, all we have discussed is that we are going to find a program in Australia.

"I have had a lot of offers from Australian trainers, but it's not what I have done in the past, and not the sort of person I am. He (Chipperfield) has done a great job."

Williams also noted Catalyst's near unblemished record under Chipperfield's care.

"We got beaten on debut. I'll put that down to the notorious kick-back at Te Rapa," he said.

"The horse just got a fright and wasn't too sure what was going on. The horse hasn't been beaten since, so I can't make a case to take a horse off a trainer who is basically unbeaten."

While Murray Baker has led the charge by NZ trainers i Australia in recent years, the country has been represented ably at Group One level this spring by Te Akau Racing stars Melody Belle, Te Akau Shark and Probabeel.

Melody Belle returns home with a win in the Empire Rose Stakes at Flemington and second in Saturday's Mackinnon Stakes, Te Akau Shark was placed in the Epsom Handicap and Cox Plate while Probabeel ran second in the Flight Stakes.