Stewards have fined trainer Leon Corstens $500 for treating his Melbourne Cup runner Zabeelionaire on race day.

Acting on a report from investigators monitoring all Cup horses, the stewards found Corstens had used a herbal treatment on a rear hoof on the advice of an RVL farrier.

Chief stewards Terry Bailey said Corstens had not attempted to conceal the treatment which he believed he was entitled to administer.

But Bailey said a request to do so should have been made to the stewards, who, he said, would have refused permission.

Zabeelionaire is clear to run in the Cup.