Imported stayer Stout Hearted has been put down following a serious hoof injury.

Stout Hearted suffered the injury when he escaped from his trackwork rider on Saturday morning and was scratched from the Hollindale Stakes at the Gold Coast.

"The injury became worse than first thought and we had to put him down," owner Geoff Grimish told Brisbane's RadioTAB.

"It ocurred in the very lower extremity of his hoof and it's something you can't treat or put a screw in.

"After the vet's advice we had to get him put down."

The five-year-old was a son of Dynaformer, the sire of Melbourne Cup winner Americain, and won last year's Group Three Kingston Town Stakes (2000m) at Rosehill.

Stout Hearted was bought by trainer Chris Waller after winning two of his first seven starts in Great Britain.

Under Waller's training, Stout Hearted four times from 13 starts and was being set for Saturday week's Group One Doomben Cup.