Trainer Ricky Maund is set to start a six-month disqualification over a raceday treatment charge from more than a year ago, after exhausting his avenues of appeal.

Racing Victoria said Maund's ban would begin on June 2 after the Court of Appeal of the Supreme Court on Thursday refused his application for leave to appeal a decision of the Victorian Civil and Administrative Tribunal.

Maund was banned by the Racing Appeals and Disciplinary Board in July last year after he was found guilty of two charges of administering, or causing to be administered, an alkalinising agent to Uncle Keithy on April 18, 2015, the day he was to race at Caulfield.

Stewards scratched Uncle Keithy from his race.

Maund applied to VCAT for a review of the RAD Board's six-month disqualification.

That application was dismissed in August and Maund took his case to the Supreme Court.

He has been training under a stay of proceedings pending Thursday's decision.