Racing Victoria stewards have elected to take no action against three trainers following investigations into positive test results to banned substances.

Robbie Laing, along with father-and-son training duo Russell and Scott Cameron, each had one horse show traces of an anabolic androgenic steroid in blood samples.

The Laing-trained Little Indian returned a positive to trenbolone in a pre-race sample at Mornington in September last year while the Cameron-trained Mrs Hardwicke tested positive to trenbolone and trendione in an out-of-competition test in January.

During their investigations stewards established both horses were administered a product used to prevent mares coming into season that contained altrenogest.

Various registered products containing altrenogest were analysed for trenbolone and trendione which the trainers in the circumstances would have been unaware of.

As a result stewards issued notices to stop using products containing altrenogest in June and and again in September this year.

With the positive samples collected before those notices being issued by RV, stewards elected to take no further action against the trainers.