Animal rights groups have denounced an “extremely cruel” industry after horse Regal Monarch was euthanised following a horror fall during race four on Melbourne Cup day.

The Chris Waller-trained horse was humanely euthanised on Tuesday evening after an incident which saw star jockey Joao Moreira ruled out of the remainder of the meeting.

“We are extremely traumatised when we hear about fatalities like this,” a spokesperson for The Coalition For The Protection Of Racehorses told The New Daily.

“But this is not a rare case. One horse loses its life every 2.6 days on Australian racecourses.

“I think it’s five fatalities in as many years from the Melbourne Cup.”

The spokesperson said the public was starting to wake up to the cruelty of horse racing.

“People are starting to learn that the party just isn’t worth it,” they added.

“We are seeing people turning away from horse racing in record numbers … we’ve seen a big shift in public opinion.”

A statement from the same organisation queried the timing of the announcement, late on Tuesday evening, about Regal Monarch’s fate.

“Despite the fact that he fell around 1pm, the death was not reported until after 8pm tonight, raising suspicions that the death was concealed to avoid bad publicity before the running of the Melbourne Cup,” they said.

However, Racing Victoria’s chief vet, Dr Grace Forbes, said deaths like that of Regal Monarch happened “infrequently”.

“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,” she said.

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

People for the Ethical Treatment of Animals (PETA) Australia said the horse racing industry was “a disgraceful demonstration of national senselessness”.

“He’s [Regal Monarch] the latest in a long line of dead horses,” they said in a statement.

“While media coverage focuses on silly hats, behind the scenes of this abusive industry, horses used for racing are made to run to the detriment of their health.

Regal Monarch was killed after falling at @FlemingtonVRC just before the #MelbourneCup. Just one of many horses who die every 2.6 days in Oz pic.twitter.com/nQfWwOHdCm

— Horse Racing Kills (@hrseracingkills) November 7, 2017

“Before they’ve even finished maturing, these 500-kilogram animals are forced to race at breakneck speeds while being whipped and pushed past their limits, supported on ankles as small as those of humans.

“That’s [137 horses dying on Australian tracks from July 2016 to July 2017] an average of more than two per week, but racing coverage glosses over the bleeding lungs, broken bones, and death.

“How many more fatalities will it take before we call time on this disgraceful demonstration of national senselessness?”

Regal Monarch won four of its 17 starts.