June 2, 2026 — 3:31pmRenowned trainers Patrick Payne and Tom Dabernig are soon to front the Victorian Racing Tribunal on positive tests to a mysterious breast cancer drug, despite the emergence of research that shows their horses could have produced the substance naturally.Payne is due before the tribunal on June 17 after his horse, Hard To Cross, returned a positive swab two years ago for formestane – a steroidal aromatase inhibitor used to treat breast cancer overseas, but not available in Australia.Patrick Payne is facing charges of formestane presentation.Getty ImagesDabernig, the grandson of Australian Racing Hall of Fame Legend Colin Hayes, is listed to appear before the tribunal on July 8 after a urine sample from his horse Ashford Street showed traces of formestane, 4-hydroxytestosterone and testosterone.The group 1-winning horsemen are two of at least 24 trainers in the thoroughbred and harness racing industries to have had horses test positive to formestane – a substance almost unheard of in Victorian racing circles before February 2023.No incriminating evidence has ever been found at the trainers’ stables or elsewhere.But this masthead first reported last week that breakthrough research emerged in March 24 that formestane could be endogenous in horses – that is, naturally occurring.The research by UK scientist Marjaana Viljanto and others, commissioned by the British Horseracing Foundation, found formestane “for the first time” in 92 urine samples of 136 horses (50 geldings, 50 mares and 36 colts, selected at random).Viljanto presented the research at the International Conference of Racing Analysts and Veterinarians 2026 at Melbourne’s Crown casino on March 24.If the study is verified and published – a peer-review process that could take 12 months – the horses will have tested positive to a substance they potentially produced themselves.But it will be too late for trainers of five stables who were fined $24,000 by the VRT on Mach 23 – a day before Viljanto’s Melbourne presentation – despite maintaining they had never done anything wrong.Tom Dabernig is expected to front the Victorian Racing Tribunal in July.Getty ImagesPayne, who has always maintained his innocence, said he understood Racing Victoria had a job to do, and that they had been helpful throughout the process.“I was more affected at the start because of the unknown – I was more accusing of those around me, ‘How has this happened?’ – but as it has gone on, I am more relaxed, knowing it probably occurs naturally,” Payne said.But vice president of the Victorian branch of the Australian Trainers’ Association Daniel Bowman said the industry had “failed” the trainers.Bowman said the UK research was “proof” in his mind that the positive swabs were an anomaly.“These trainers are getting fined for something that they haven’t done,” Bowman told this masthead.“How can you fine them as a deterrent, but then also, on the other hand, admit that they haven’t knowingly given anything to the horse?”Daberning was contacted for comment.The Melbourne conference at which Viljanto spoke, ICRAV 2026, opened with a three-course seated lunch and drinks in the Skyline Lounge at Flemington races on Saturday, March 21.The trainers – Smiley Chan, Julius Sandhu, Symon Wilde, Mark and Levi Kavanagh, and Ash and Amy Yargi – were fined for formestane presentation (a horse testing positive to a banned substance on race day) two days later on Monday, March 23.Trainer Daniel Bowman (left) and jockey Declan Bates after Begood Toya Mother won the 2019 Sir Rupert Clarke Stakes.Getty ImagesViljanto presented her research, Investigations Into the Possible Endogenous Nature of Selected Anabolic-Androgenic Steroids in Equine Urine, at ICRAV 2026 on Tuesday, March 24.Two members of the ICRAV 2026 organising committee – Racing Analytical Services Limited scientific manager Dr Adam Cawley and Racing Victoria regulatory vet Dr Edwina Wilkes – provided evidence during earlier sittings of the formestane tribunal hearings in December last year.This masthead does not suggest that Racing Victoria acted improperly or ignored relevant science. At the time of the tribunal hearings, Viljanto’s research had not been published or peer-reviewed, and its conclusions remain unvalidated.Bowman said the industry had already wasted too much money on prosecuting formestane cases.“It’s clear none of these trainers have done anything wrong, and yet we’re pursuing them through charging them and taking them through the proceedings, paying lawyers and solicitors money to fight the cases for them,” he said.“It’s just irresponsible use of funds.”Bowman, 39, said he and his wife, Denita, had recently sold their 30-acre training property at Warrnambool and downsized from 25 horses to three because it had “become too hard for a smaller-to-medium-sized stables to compete” in Victoria.The group 1-winning trainer of Begood Toya Mother said the formestane cases had contributed to him losing confidence in the industry.“You’re basically taking a horse to the races, running Russian roulette every time because they can’t prove where it [formestane] is coming from,” he said.“I can’t afford, if I get one of these positives randomly, to fight it.”A Racing Victoria spokesperson said, “formestane and its metabolites remain strictly prohibited substances under the Australian rules of racing and the stewards can’t shy away from their responsibility to apply the rules and uphold the integrity of the sport”.Racing Victoria has commissioned research alongside RASL to determine if formestane and its metabolites are endogenous at low levels in racehorses. RASL, an independent laboratory, hosted ICRAV 2026.Formestane is on the WADA banned substances list, but the association introduced a testing threshold for athletes after research showed it was endogenous at low levels in humans.News, results and expert analysis from the weekend of sport sent every Monday. Sign up for our Sport newsletter.More:Racing integrityVictorian racingHorse racingDrugs in sportFrom our partners