The secret identity of a lawyer who acted as a double-agent to dob on her own clients during Melbourne’s infamous gangland wars was revealed for the first time on Friday afternoon.

The woman is Nicola Gobbo, a once high-flying criminal barrister who is now living as a suburban mum and community volunteer in Melbourne’s affluent southeast after refusing witness protection.

The revelation police were using the woman known until now as ‘Lawyer X’ to inform on her clients has led to a royal commission in Victoria and rocked the justice system.

It has cast doubt on whether some of the nation’s most dangerous killers and drug dealers, many of whom featured in the Underbelly TV series about Melbourne’s gangland wars, received a fair trial.

At least 20 criminals could now apply to be freed.

The niece of former Governor of Victoria and judge Sir James Gobbo, Ms Gobbo received a private education in Melbourne before studying law at the University of Melbourne and later joining the Australian Labour Party.

She became one of the youngest women admitted to the bar aged 25 and rose to prominence in the 1990s and 2000s representing the likes of drug lord Carl Williams during a decade-long underworld war which resulted in the murders of 36 criminal figures.

It was a time of frustration for police amid the constant bloodshed and authorities were under enormous public pressure to secure convictions.

Nicola Gobbo has been unmasked as ‘Lawyer X’. Photo: ABC

In one high-profile case, Ms Gobbo was a key prosecution witness against former drug squad detective Paul Dale. He was accused of having drug dealer and police informer Terence Hodson and his wife Christine murdered in their East Kew home in 2004.

But she dropped out apparently because of poor health and later applied to sue Victoria Police for failing to protect her when she agreed to testify.

Charges against Mr Dale were dropped due to insufficient evidence.

During a separate probe, Mr Dale had told a 2008 Australian Crime Commission hearing he had been having extramarital affairs he called “drunken escapades” with Ms Gobbo.

He denied that he had approached Carl Williams, a client of Ms Gobbo, to arrange the murders of the Hodsons after it was alleged he had had secret dealings with the underworld boss.

Homicide detective Sol Solomon later told a Supreme Court that after the ACC hearing Ms Gobbo approached police and offered to wear a wire to a planned meeting with Mr Dale.

The recording helped secure charges of giving false or misleading answers to the ACC, and Ms Gobbo was to be used as a prosecution witness.

But she was again dropped from that case, this time amid safety fears after a sympathy card sent to her lawyer referred to her as a ‘dog’ and read: “Tell your client she is dead, dogs die dead”.

That was just one of a number of times Ms Gobbo assisted police as professional, personal and ethical lines were blurred, with the lawyer later boasting that she had secured more than 5500 informer reports.

Infamous criminal Tony Mokbel was one of Ms Gobbo’s clients. Photo: Getty

At the same time as defending criminals in court, Ms Gobbo was also informing on them to police, sometimes in the same day.

Victoria Police has been fighting to keep Ms Gobbo’s identity secret, fearing she would be targeted if she was named.

But a court has ruled the public’s right to examine the police force’s actions outweighs the need to protect the former barrister known until now as ‘Lawyer X’ or ‘Informer 3838’.

Her identity and actions were already known in the criminal world.

Ms Gobbo’s choice to break the trust of the high-profile gangsters she represented – and turn her back on ethical obligations – has opened a window for some of the nation’s most serious criminals to potentially be freed, including drug lord Tony Mokbel.

Mokbel, who was jailed for 30 years over drug trafficking, is recovering after an attack at Barwon Prison last month.

Ms Gobbo had been an informant in his case and hundreds of others. 

A royal commission into the scandal is set to begin next month to scrutinise who knew about the informer program and how widespread the practice of getting lawyers to snitch on their clients has been.

Its scope was widened after police revealed their ‘Informer 3838’ was first recruited in 1995, not 2005 as previously thought, and other people who held obligations of confidentiality were also used for information.

Media lawyers have since been arguing for the gag order to be lifted for four years, and after years of legal battles the courts have ruled in favour of identifying Ms Gobbo for the sake of public interest.