Cranbourne trainer Ricky Maund has been found guilty of treating a horse on race day as Racing Victoria continues its crackdown on illegal activity in the industry.
Maund had been charged after stewards found fresh blood on the neck of Timely Truce following a stable raid on November 10.
The horse had been scheduled to run in a Listed race at Flemington that day but was withdrawn by stewards.
Maund faces a penalty, which under the rules can include disqualification and a fine of up to $75,000, but the case has been adjourned until Monday to enable the trainer to make a submission.
He claimed the puncture mark found on Timely Truce had been the result of a scab from an injection he had given the horse legally the previous afternoon.
Maund said the fresh blood was possibly the result of him pulling the horse's neck ring back over a scab shortly before stewards arrived at his stable.
He told the hearing he had injected Timely Truce with Aminolite, a legal mix of vitamins and amino acids on Friday evening, but his evidence was contradicted by RV veterinary surgeon Dr Grace Forbes.
Dr Forbes said an Aminolite injection left a small puncture mark which would heal in minutes.
"If the injection was given 15 hours earlier there would be no reason for bleeding," she said.
Maund claimed that he had tossed the equipment he had used to give the Aminolite injection into the back of his utility and it had blown off while he was driving.
RV Compliance Assurance Team member Dion Villella told the hearing that Maund had been in an "agitated" state when he and another steward walked into the stable area on Saturday morning.
Maund denied he had treated the horse on race day and said he stood by his word "110 per cent".
The finding follows Queensland trainer Nathan Schofield's 12-month ban and Robert Smerdon's $10,000 fine on similar charges.
There are ongoing inquiries into the activities of trainers Con Karakatsanis and Jim Conlan.