Distressing vision of one of Darren Weir's prized horses being tormented with an electric prod in preparation for last year's Melbourne Cup may be a crucial piece of evidence in the case against the disgraced trainer and two of his associates.
The emergence of the video at the start of a new spring carnival directly links the Weir scandal to Australia's greatest horse race.
Video footage obtained by Victoria Police detectives and shown to racing authorities shows Red Cardinal being "jiggered" in the neck by stablehand Tyson Kermond as it "jog trots" on a treadmill inside Weir's Warrnambool stables, sources have told The Age.
The footage, which runs for about 20 seconds, allegedly shows Weir and stable foreman Jarrod McLean looking on as the horse is repeatedly subjected to the painful ordeal on the weekend before the running of the Cup.
A source who has watched the footage described it as "terrible" and "shocking". Two further sources confirmed that Red Cardinal's run in the Cup was material to the case against Weir.
Weir, McLean and Kermond are each facing criminal charges under Victoria's animal cruelty laws including torturing, abusing, overworking and terrifying a thoroughbred horse and causing unreasonable pain or suffering to a horse.
The trio are also charged with conspiring to defraud stewards and other offences in one of the most damaging scandals to hit Australian racing.
A fourth man, 31-year old retired jockey William Hernan, is charged with using corrupt information. Sources familiar with the investigation said this related to a $50 bet on a horse suspected of being jiggered.
Red Cardinal began the Melbourne Cup as a $31 chance and laboured badly over the two miles to finish last.
The jockey who rode the horse in the Cup, Damien Oliver, said after the race that Red Cardinal "didn't have enough air" to finish the two-mile classic. The owner of Red Cardinal, Australian Bloodstock director Jamie Lovett, told The Age he believed the horse choked on the bit.
There is no suggestion of wrongdoing by Oliver or Lovett.
The alleged use of an illegal jigger on Red Cardinal has tainted the event that made Weir a household name three years earlier, when Michelle Payne rode home on Prince of Penzance, a 100-1 longshot trained by Weir, to win the Melbourne Cup.
Detectives from the police Sporting Integrity Unit, who were last August invited by racing integrity officials to investigate allegations of animal cruelty and corruption against Weir and his associates, scrutinised the famed 2015 Cup and found no evidence of corruption, and there is no suggestion Payne was involved in any wrongdoing.
Another feature race of last year's Flemington carnival, the Mackinnon Stakes, and the Grand National event run at Sandown earlier in the year were also closely examined by police.
It is believed that these races, although under investigation, do not form part of the charges against Weir and his co-accused currently before the Melbourne Magistrates Court.
Police in January raided Weir's properties in Miners Rest and Warrnambool. At his racing headquarters at Miners Rest, police seized three jiggers from Weir's bedroom.
Weir is serving a four-year ban from racing after pleading no contest at a Racing Appeals and Disciplinary Board hearing to possessing the jiggers and conduct prejudicial to racing.
The board made no finding that he used the jiggers on any of his horses. Possessing jiggers is not a crime, but is a breach of the rules of racing.
McLean, Kermond and Hernan were all called to appear before a steward's inquiry on Thursday. The hearings were conducted in private.
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