A secret recording shows gangland lawyer Nicola Gobbo provided crucial information that allowed police to uncover the world's largest ecstasy haul.

Key points: Nicola Gobbo was holding shipping documents for a client, Rob Karam, when she passed copies to police

Nicola Gobbo was holding shipping documents for a client, Rob Karam, when she passed copies to police The documents contained information about a shipment of 15 million ecstasy pills

The documents contained information about a shipment of 15 million ecstasy pills Karam is one of a group of crime figures jailed over the haul now eying freedom due to Ms Gobbo's double-dealing

The June 5, 2007 recording, played to the Lawyer X royal commission, shows Ms Gobbo's intimate involvement in the now-infamous tomato tin drug bust.

During the conversation with two police officers, Ms Gobbo handed them shipping documents that identified the container carrying 15 million ecstasy pills hidden in tins of tomato paste being imported from Italy.

Police officer: We can have these? Nicola Gobbo: This is your copy. Police officer: Neat

She got the documents, known as a bill of lading, from a client named Rob Karam who was later convicted of importing the drugs, which were worth about half a billion dollars.

He's now planning to appeal against his 35-year sentence on the grounds Ms Gobbo's involvement denied him a fair trial.

The operation also netted a series of major crime figures including Pasquale Barbaro and John Higgs.

Convicted drug trafficker Rob Karam has a legal representative at the royal commission and may appeal against his conviction. ( Supplied )

Both men have legal representatives at the Lawyer X royal commission and may also appeal against their convictions.

The recording shows Karam had given Ms Gobbo the shipping documents for safekeeping in June 2007, around the time she was acting as his barrister in a trial for separate drug importation charges.

She told officers she had time to photocopy the documents before Karam wanted them back.

Nicola Gobbo: Then at lunchtime — see, lucky I photocopied them — 'cause at lunchtime we're talking around the corner, he goes, "I need to come and get those documents." So he came down to my office with his brother, and his brother took the documents away.

The Lawyer X scandal has already led to a man convicted of murder being freed because he did not get a fair trial.

Faruk Orman spent 12 years in jail before the Court of Appeal quashed his conviction for being the getaway driver in a gangland hit.

It emerged Ms Gobbo, while acting as Mr Orman's lawyer, was secretly working with police to convince a key witness to give evidence against him.

Mr Orman is expected to sue the State Government for millions of dollars in compensation.

Dozens of criminals have been informed their convictions may also have been compromised by Ms Gobbo.