Gangland figure Tony Mokbel suffered a substantial miscarriage of justice because he was misled and deceived for years before pleading guilty to drug offences, his lawyers have argued.
Mokbel is fighting to quash drug-trafficking and importation convictions in the Victorian Court of Appeal, claiming they were tainted because of barrister-turned-informer Nicola Gobbo.
Ms Gobbo was registered as a Victoria Police informer from 2005 to 2009 and was acting as Mokbel's lawyer for four years before he fled to Greece in 2006.
She continued to advise him when he was extradited to Melbourne in 2008.
Barrister Tim Game SC argued Ms Gobbo not only "pretended" to be Mokbel's lawyer while informing, she encouraged two of her clients to make statements against him.
The statements from the two men, known under the pseudonyms Mr Cooper and Mr Bickley, were key to the prosecution of Mokbel, Mr Game told the court.
He argued there would have been insufficient evidence to charge Mokbel on the drug-trafficking offences without the men rolling.
Mokbel in April 2011 pleaded guilty to two counts of trafficking a drug of dependence and one count of incitement to import a prohibited substance after striking a deal with prosecutors.
He tried to withdraw his plea but his application was refused in March 2012 and he was ultimately sentenced to 30 years' jail in July of that year.
Mr Game told the court former director of public prosecutions and current Victorian judge John Champion was aware of Ms Gobbo's status in June 2012.
He argued Justice Champion could have told the court there was an issue he could not disclose, which would lead to a public interest immunity claim.
"If you're in a situation where you need to disclose, you have to do something because doing nothing is not an option," Mr Game said.
The barrister told the court as a result of the lack of disclosure, Mokbel and the courts were misled for years.
"Fraud is what has occurred in this case .... it has been pulled together by dishonest means" Mr Game said.
He argued given Mokbel served 18 years in prison before he was bailed in April, it would be open to the court to acquit him on the three charges if his appeal is successful.
But Office of Public Prosecutions' David Glynn told the court the appeal should fail because the grievances Mokbel had outlined did not amount to a miscarriage of justice.
Mr Glynn said Ms Gobbo was not acting as Mokbel's legal representative at the time he pleaded and, while the cases against him would be weakened without the evidence of Mr Cooper and Mr Bickley, they were still viable.
The prosecutor argued if the court disagreed and instead granted the appeal, the justices should order a retrial as it was in the public interest for the charges to be prosecuted.
"He now has that knowledge (of Ms Gobbo's status) - a fair trial can now be had," Mr Glynn said.
The appeal hearing before Justices Stephen McLeish, Maree Kennedy and Stephen Kaye will continue on Thursday.
