Following an investigation into the use of Sungate on 43 horses in nine different racing yards, the British Horseracing Authority announced on Wednesday that there would be no charges brought against the licensed trainers involved.

Sungate, which is not licensed in Britain but was legally imported to the country from Italy under veterinary certificate by Newmarket practice Rossdales & Partners, contains stanozolol, an anabolic steroid, which therefore means it is prohibited for use on racehorses in training.

A statement issued by horeracing’s regulatory body read: “The BHA became aware of the nature of Sungate and its use on horses in training following a visit to Gerard Butler’s yard in February 2013 as part of its testing in training sampling programme, from which nine horses produced positive tests for stanozolol. It became apparent that a veterinary practice, which had legally imported Sungate under licence into the UK, was prescribing this product and had recommended its initial administration to horses in training. The BHA subsequently met with representatives of the veterinary practice in question. As a result of that meeting the BHA became aware that Gerard Butler was not the only trainer to whom it was recommended that Sungate be administered to horses in the trainer’s care.”

Thirty-eight trainers – all thought to be clients of Rossdales – were questioned by the BHA during the course of the investigation, which began shortly after Godolphin trainer Mahmood Al Zarooni was banned from racing for eight years after 22 horses under his care tested positive for anabolic steroids. A total of 43 horses were found to have been given Sungate under veterinary advice from early 2010.

It remains a matter of serious concern that a veterinary practice recommended and administered a product containing anabolic steroids

“These administrations were recorded in the medication records required to be kept by trainers in accordance with the Rules, and in the clinical histories of the horses which were obtained, with the trainers’ consent, from the veterinary practice,” read the BHA press release.

Adam Brickell, Director of Integrity, Legal and Risk for the BHA, outlined the reasons for the trainers in question escaping punishment: “Having carefully considered our options under the Rules, including taking legal advice and reviewing previous cases, we have concluded that there would no reasonable prospect of a Disciplinary Panel finding that these trainers have breached the Rules of Racing.

“Under the current Rules of Racing, in the absence of any positive samples, charges could only be brought in cases such as this if there is evidence that the trainer concerned has acted in a manner prejudicial to the integrity, proper conduct, or good reputation of the sport. In these cases there was no such evidence. This is because the nine trainers in question only allowed their horses to be administered with the product on the advice of – and by – veterinary surgeons to treat orthopaedic conditions.”

The charges brought against Gerard Butler in June also relate to the use of Sungate but include the allegation that the trainer administered the drug himself via intra-articular injection (to the joint), an act which should only be conducted by a veterinary surgeon. The date of the BHA disciplinary hearing in this case is yet to be announced.

“It is important to note that the product at the centre of this investigation is a treatment designed to be injected into a horse’s joints, and is very different to that which might be used in an intramuscular anabolic steroid product,” said the BHA’s interim Chief Veterinary Officer Jenny Hall following the announcement that no charges were to be brought against the nine trainers other than Butler, who have not been named.

“The recommended dose of Sungate varies according to the size of the joint to be treated, but a typical intra-muscular injectable anabolic steroid product has around ten times the concentration of anabolic agent compared to Sungate, and a recommended dosage would generally contain around 50 times the volume of anabolic agent administered in one Sungate treatment.

“In addition, it follows that when a veterinary product has been used to treat an orthopaedic condition there is a recovery period associated with the treatment before a horse can return to the racecourse. The clinical histories of the horses in question confirmed that in each case where Sungate had been administered by veterinary surgeons it had indeed been done so to treat an orthopaedic condition.

“However, it remains a matter of serious concern that a veterinary practice recommended and administered a product containing anabolic steroids, which are prohibited substances under the Rules of Racing, to these horses.”