Conduit, ridden by Ryan Moore, went on to win the race
A man who threatened to kill a top racehorse in a bid to avoid gambling debts of £55,000 has been given a 34-week suspended jail term.
Andrew Rodgerson, 26, told Conduit's owner the horse would be stabbed if it ran in the King George VI and Queen Elizabeth Diamond Stakes last July.
He was arrested before the Ascot race, which was run amid tight security.
Rodgerson, from Rochdale, who admitted threatening to damage property, was sentenced at Bury Magistrates' Court.
An original charge of blackmail was dropped.
Conduit, which has an estimated stud value of £5m and was favourite for the race, went on to win on 25 July.
Rodgerson, of Craiglands, Balderstone, sent a series of text messages and e-mails to Peter Reynolds, the general manager of the Ballymacoll Stud Farm in Ireland which owned Conduit, Bolton Crown Court, sitting in Bury, heard.
Ten days before the race his first message read: "Dear Peter, we would just like to warn you should Conduit run in the King George then the horse will be killed."
Increased security was laid on by the British Horse Racing Authority (BHA) during the horse's journey to Ascot and when it was stabled at the racecourse.
But Rodgerson was found before the race after his address was identified from the e-mails he sent to the general manager, in which he again demanded the horse should be withdrawn.
Judge Angela Nield, sentencing, described his crime as a "foolish escapade" which could have had a serious impact on the horse racing industry.
"I am clear that the gravity of the offence is the potential impact to the racing industry of this type of offending becoming more prevalent," she said.
During police interview Rodgerson admitted making the threats because he had become heavily in debt to a betting ring, the court heard.
Duncan Wilcock, prosecuting, said people would ask him to place three or four bets per day with a usual wager being up to £400 each way on a horse.
"This particular bet was an accumulator where other horses had already won and if Conduit won then Rodgerson said he would be in debt to the syndicate for £55,000," Mr Wilcock said.
"He explained he had made a mistake on one of the bets he should have placed."
Joseph Hart, defending, said Rodgerson had mistimed the bet and realised if it won he would owe the syndicate the huge sum, leaving him "utterly terrified".
He said: "These were powerful men, he thought these were shadowy men. He thought perhaps they would be people who would hurt him.
"So initially he lied to them that someone had taken the betting slip but then the syndicate said they would find him.
"The panic continued and he committed this frankly unsophisticated and deeply stupid crime."
Rodgerson told police he had no intention of carrying out the threat.
Speaking after the hearing, Det Sgt Andrew Butterworth, of Rochdale CID, said: "Rodgerson made, what were to his victims, very real and very disturbing threats.
"His actions were foolish and reckless."
Rodgerson's sentence was suspended for two years and he was also ordered to carry out 240 hours unpaid work.