Caulfield trainer Henry Dwyer faces a fine for taking a horse to a jumpout with an anti-inflammatory drug in its system.
Stewards charged Dwyer with a breach of AR 177A after analysts detected Phenylbutazone and Oxyphenbutazone (a non steroidal anti-inflammatory) in a urine sample at the Burrumbeet jumpouts on June 22.
While the substances are often used in stables, horses cannot have them in their system in an official trial or a jumpout.
Dwyer has indicated to stewards in writing that he would plead guilty to the charge and the stewards' report stated they would invoke a local rule to impose a fine of $5000 or less for a minor offence.
The stewards will determine Dwyer's penalty at a hearing on Thursday.
Dwyer is the third trainer to face an investigation for a positive swab at the Burrumbeet jumpouts with runners from the Darren Weir and Simon Morrish stables subject to investigations relating to runners on the day.