Regal Monarch, the horse that broke down in race four on Melbourne Cup day, has died.

The Chris Waller-trained Regal Monarch, which went amiss as the field turned for home, was put down on Tuesday night.

Regal Monarch being led into an equine ambulance after the fall at Flemington. Credit:AAP

Jockey Joao Moreira was also injured in the fall, forcing him from his ride on Thomas Hobson in the Cup.

"Regal Monarch was immediately attended to by our veterinary team after a fall in race four and was transported to the University of Melbourne Veterinary Clinic in Werribee for further assessment," Racing Victoria's head vet Dr Grace Forbes said.

"It is with sadness that we can confirm that the horse has been humanely euthanised on veterinary advice as a result of the injuries sustained. This decision was made in the best interests of the horse.



"Incidents such as this happen infrequently, with Victoria having one of the best safety records in world racing."

Moreira was stood down by the club doctor from the remainder of his rides, which included the Irish raider Thomas Hobson. Moreira walked back to the mounting yard and hobbled out of Flemington when he left the course with a minor leg complaint.

Apprentice Ben Allen was sent an SOS to ride Thomas Hobson, which finished sixth behind Rekindling.