Two men jailed over a major cocaine import from Mexico have been granted fresh trials after a judge misdirected their original jury.
Danny Awad, the son-in-law of underworld figure Mick Gatto, and his co-accused John Tambakakis won their appeal to the High Court on Wednesday.
The pair were jailed for a decade over the import of 22.4kg of cocaine in a consignment of printers shipped to Melbourne in May 2017. The drugs had an estimated street value of up to $12.4 million.
Tambakakis gave evidence at a County Court trial, where a jury found them guilty of attempting to possess a commercial quantity of an illegally imported drug.
But the convictions were quashed by the High Court, finding a substantial miscarriage of justice occurred over the judge's directions to the jury about how to deal with Tambakakis' evidence.
Prosecutors alleged at trial that Tambakakis collected and stored the shipment, and later delivered a van used to transport the drugs.
It was alleged Awad was in joint possession of the drugs, a case which depended on him having been in the van with Tambakakis.
In his evidence Tambakakis had said he believed the drugs were steroids, which he had previously imported, and that Awad had not joined him in the van.
Judge Mark Dean told the jury that an innocent person might choose to give evidence in their own trial.
"On the other hand, secondly, a guilty person might decide to tough out cross-examination in the hope or believe that he will be more likely to be believed and his defence accepted if he takes the risk of giving evidence," he said.
The judge also noted that while they should treat Tambakakis' evidence the same as any other witness, they should bear in mind he would probably be under more stress than any other witnesses.
Those directions were found to be prohibited.
Prosecutors argued it was so innocuous that the jury would have disregarded it, but the High Court found the Crown's attempts to minimise the effect should be disregarded.
"By leaving the jury with the choice to approach Mr Tambakakis' evidence ... on the basis he was a guilty person deciding to 'tough out cross-examination' there was a conflict with the directions given on the onus and standard of proof," Chief Justice Susan Keifel and Justice Jacqueline Gleeson wrote in one of three separate judgments by the court.
By a majority the court ordered the appeals be allowed, the pair's convictions overturned and a fresh trial ordered.
Justice Simon Steward was a lone dissenting voice, arguing the appeals should have been dismissed.
While he agreed the directions were prohibited, he didn't believe they constituted a substantial miscarriage of justice.