Expensive import Changingoftheguard has died after complications developed during surgery at Lindsay Park.

Australian interests bought the son of Montjeu for a reported $1 million with last year’s Melbourne Cup in mind before the four-year-old was sensationally scratched on race morning.

Racing Victoria fined trainer David Hayes for calling vets “knuckleheads” shortly after the incident.

The former Aiden O’Brien-trained galloper raced once for the Hayes camp for a well-beaten 10th in the Group II St George Stakes (1800m) at Caulfield on February 20.

Hayes abandoned Australian Cup plans after Changingoftheguard galloped poorly at Flemington in the lead-up to last Saturday’s meeting, connections deciding to geld the stayer with the 2010 Melbourne Cup in mind.

However, Changingoftheguard was unable to survive a routine gelding operation with vets forced to euthanize the stayer after he suffered a ruptured bowel.

''That has never happened at Lindsay Park before and we've had hundreds, even thousands, done,” Hayes told The Age.

“Sometimes a horse can injure a leg when getting up after an operation, but not this.''