Two Australian trainers found guilty of doping horses successfully overturned their multi-year bans Friday after a tribunal found evidence used to prosecute them inadmissible.
Danny O'Brien and Melbourne Cup winner Mark Kavanagh were suspended for four years and three years respectively by the Victorian Racing and Appeals Disciplinary Board last year.
The ban took place against the backdrop of a spate of positive tests returned by horses for a prohibited substance, cobalt.
The banned trainers vowed to appeal the decision, saying they were not aware of the level of cobalt in vitamin supplements.
"The procedure for testing for cobalt in equine urine... departed from the requirements" in the rules of racing, Justice Greg Garde of the Victorian Civil and Administrative Tribunal said.
"The legal consequence is that the test results are inadmissible in evidence against the trainers.
"As a result, the application for review must be allowed, and the charges against Kavanagh and O'Brien dismissed."
O'Brien, who won the 2007 Caulfield Cup, slammed Racing Victoria after the hearing, saying the pair had been "completely innocent".
"We are going to read the judgement. The summary from Garde was very strong that we were completely innocent and Racing Victoria have got issues," Melbourne's The Age reported him as saying.
"Once we understand the ins and outs of it, we will be reserving all our rights."
Australian racing rules describe cobalt as a naturally occurring trace element which may normally be present in horses at very low levels. It is also found in vitamin B12.
Cobalt is believed to improve endurance, however, trainers have been warned of severe side effects.
The Australian Racing Board set a threshold level of 200 micrograms per litre with bans enforced for higher concentrations from January 1, 2015.