Smart sprinter The Peak was euthanised after breaking down in the Prime Minister's Cup on Saturday.

The Peak faltered near the 100m when making a strong run to challenge the eventual winner Neo.

The Bart and James Cummings-trained sprinter was taken from the track to a veterinary hospital where it was hoped to save him.

However, vets found the injury to his near-hind leg was too bad.

Chief steward Alan Reardon said The Peak had a fractured leg and X-rays showed it was impossible to save him.

The Peak won seven races and raced in Hong Kong before returning to Australia.

Trainer Stuart Kendrick will discuss carnival plans for Neo with the gelding's owners after the five-year-old ended a frustrating run of minor placings since arriving from New Zealand.