Robert Clement, Anthony Mabbott and Cody Morgan fronted a committal hearing that lasted almost five hours in Tamworth Local Court yesterday to determine if the trio will stand trial on a string of charges.

The men are the first to be tried under the criminal laws introduced in September 2012, which have been closely watched by many across the thoroughbred and harness racing industries.

The trio - who were first charged in May last year with offences spread across both racing sectors - include charges they facilitated conduct that corrupted the betting outcome of an event as well as used corrupt conduct information to place bets.

Morgan and Clement are accused of drenching 2013 Tamworth Cup winner Prussian Secret prior to the race before detectives attached to Strike Force Trentbridge coordinated raids on their properties with fears the same horse was to be drenched prior to the running of the Gunnedah Cup.

Barrister for Clement John Korn said the essence of the charge meant the Crown must prove that the trainers drenched the horse with a substance that was performance enhancing.

"The evidence shows my client ... believed, wanted, intended or hoped for ... clearly evidence my client wanted there to be a performance enhancing," he told the court.

"It doesn't matter a hoot what someone wanted to happen."

Mr Korn added there was no pre-race blood sampling on Cup day to indicate Prussian Secret topped the TC02 industry threshold, adding post-race sampling is considered unreliable because of fluctuating levels.

"There is no scientific evidence and it has to be scientific that his horse was performance-enhanced," he said.

"This case is nothing more than constructive speculation."

The brief of evidence against the accused spans five volumes of folders containing more than 2000 pages, including months of phone taps on the trio.

Crown prosecutor Jane Krippner said the crown was relying on alleged admissions in intercepts from Morgan that the horse was to be administered the same drench as the Tamworth Cup for its next race.

"It's circumstantial evidence clearly," she said.

But she said the rising levels in blood samples found in Prussian Secret "can be concluded that there must have been human intervention," as well as an intercept from a witness telling Morgan the horse was "five lengths further to the front than it would have been."

After hours of legal argument, Magistrate Robert Rabbidge said he needed to reserve to consider his verdict on whether the case would head to trial.

"There is a lot to think about," he said.

He will hand down his findings in June.