The Racing Appeals and Disciplinary Board found the father and daughter training duo guilty of administering a substance - being cobalt - above the permitted threshold in November 2018.

The duo was banned for a year at the time, based on elevated cobalt readings that were recorded in two different horses in two different years.

Darragh was found to have elevated readings at meets in 2015 and 2016. Stablemate Gold A Plenty also returned elevated cobalt readings in 2016.

The pair lodged an appeal with VCAT the day after the guilty verdict and were granted a stay of proceedings to continue training their horses while they appealed the ban.

The trainers did not dispute the elevated readings but denied administering the horses cobalt before or on race day and told the hearing they, "are as mystified as everyone else about how the results came to be".

Terry O'Sullivan told the Mail-Times on Tuesday that they've "most definitely never used cobalt or administered it to their horses."

"We most definitely have never used cobalt in any way shape or form with our horses," he said.

In evidence, the trainers consistently said that they made no changes to the horses' usual feed and supplements regime after the first elevated reading, nor were there any changes in staff.

VCAT senior member Anna Dea said "the trainers never suggested the cobalt administration occurred by mistake, for example as a result of administration of a substance too close to the relevant race day or of a greater amount than intended".

Ms Dea relied on expert reports in finding the breaches of Australian Rules of Racing proven.

Terry O'Sullivan told the Mail-Times that Ms Dea did not prove the trainers guilty, but "found them guilty on circumstantial evidence."

Central to the ruling was a statement made by Racing Victoria's general manager of veterinary services Dr Grace Forbes, regarding the large quantity of cobalt found in the horses' urine.

Cobalt increases the number of red blood cells and generates a greater ability to carry oxygen through the body. In turn, it's believed a horse can maintain peak performance levels for longer.

The A-sample of all three breaches returned readings of 600 micrograms per litre of urine - three times the then legal limit.

"I accept Dr Forbes' undisputed expert opinion that the administration of large doses of cobalt must be considered to be an attempt at blood doping with the intention of achieving an unfair advantage because there is no rational medical or nutritional purpose for administering large quantities of cobalt to a horse," Ms Dea wrote in her decision.

An expert report prepared by Dr Stuart Paine, an associate professor of veterinary pharmacology at the University of Nottingham, stated that the probability that a member of the normal horse population who ingests cobalt as part of a natural supplements regime would produce a reading of 600 micrograms per litre was 1 in 130 billion.

The trainers did not dispute the expert evidence.

Ms Dea noted that for the first time at the VCAT hearing, the suggestion was made that another person, potentially a past or current employee, may have administered the cobalt.

In interviews with Racing Victoria stewards throughout investigations, neither Terry nor Karina O'Sullivan had accused an employee of being involved.

As part of evidence given at the hearing it was revealed that in early 2016 the trainers hired two former detectives to investigate the elevated readings by interviewing staff. The former detectives found no evidence that any employees were complicit.

Ms Dea rejected the idea that an employee or unidentified stranger administered the cobalt to the two horses.

"The only probable explanation that is consistent with the evidence is that the trainers administered or caused the cobalt to be administered," she said.

"While it has not been possible to definitively identify which of them did so, I am comfortably satisfied one of them administered injections of a substance that contained large doses of cobalt, and the other knew and approved of the substance being administered or other authorised the other to administer substances of whatever kind the second person chose, including substances which contained prohibited substances."

Mr Dea said she was alarmed at some of the evidence given to her and the Racing Appeals and Disciplinary Board about the stable's practices of administrating unregistered substances to horses.

"The evidence led me to conclude that the trainers were willing to give any almost any substance a go if it had been recommended by someone they knew and trusted, qualified or not, or because they had researched it on the internet," she said.

"I have concluded that at the relevant time it was possible the trainers were ignorant that they administered or caused to be administered to Darragh contained cobalt. That still amounts to causing administration."

"The only explanation for the trainers' conduct was that it was an attempt at blood doping with the intention of achieving an unfair advantage.

"The trainers' current belief that cobalt does not enhance performance and their shared view that engaging in that conduct would, therefore, make no sense, is beside the point. Whether the attempt was logical or not, it is the only available explanation consistent with the evidence for the administration which occurred."

Penalties will be discussed at an administrative meeting on January 28, 2020.

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