Racing Victoria has advised trainers and vets to stop using products containing altrenogist as they may contain the banned substance trenbolone.
Victorian trainers and vets have been advised to stop using products containing altrenogest.
Racing Victoria's Integrity Services Department says it has been made aware products containing altrenogest may contain levels of trenbolone and or trendione, which are banned substances with extended detection times.
RV said it was liaising with the manufacturers to clarify the situation and would provide the results as soon as they were available.
Altrenogist is used in products designed to regulate the cycles of fillies and mares.