Leading Western Australian sprinter Dark Target has died.

Trained by Chris Stelmach, the five-year-old gelding by Danetime suffered a heart attack post-race as he was being led back to his horse stall following the running of the $125,000 Group 3 Prince Of Wales (1200m) at Ascot on Saturday.

The prolific winner finished an uncharacteristic last in the ten-horse field behind Idyllic Prince.

Previous to today, Dark Target had only finished worse then fourth on only one occasion and that came in the Group 2 WA Guineas (1600m) when clearly unsuited by the longer journey.

A winner of eight from 19 starts and with earnings just shy of $400,000 Dark Target's last win was ironically recorded in last year's edition of the Prince Of Wales.