Nearly 1300 people might have been affected by turncoat lawyer Nicola Gobbo, who acted as an informer for Victoria Police.
The revelation came on the final day of a royal commission inquiry into the force’s use of Ms Gobbo.
The gangland lawyer was registered three times as an informer by Victoria Police and was officially promoted to “supergrass” status within the force.
The inquiry heard on Friday that 1297 matters have been identified as “requiring investigation” to determine if they might have been affected by Ms Gobbo who informed on her clients.
Those people were either legally represented by Ms Gobbo or received legal advice from her.
State and federal prosecutors have already notified more than 40 people that their convictions may have been tainted by her tips.
Four appeals are already underway while one conviction – Faruk Orman’s for the murder of Victor Peirce – has already been overturned as a direct result.
Friday marks the 127th and final day of public hearings into Ms Gobbo’s informing, which involved three periods from 1995 until 2009.
The inquiry has heard from more than 80 witnesses in person, while more than 80 more have provided written statements.
Lawyers have trawled through more than 145,000 documents and upwards of 1350 exhibits have been tendered since hearings began in February last year.
A small number of public hearings in April will examine policy issues surrounding police management of informers with legal obligations.
Commissioner Margaret McMurdo is due to hand down a report on her findings on July 1.
Ms Gobbo was first recruited as a law student in 1995 when she turned on a former boyfriend for drug dealing.
In 1999, she was registered again while trying to offer police tips on fellow lawyers she accused of money laundering.
Her longest stint ran from 2005 until 2009 when she gave evidence against clients, including drug kingpin Tony Mokbel and underworld killer Carl Williams.
Ms Gobbo has admitted she acted as an agent for police instead of in the best interest of her clients.
“Was I accumulating information and, on one level, trying to impress people? Yes, I was,” she told the royal commission during an earlier hearing.
“Do I regret it now? Yes. Every day.”
Inspector John Nolan and former detective senior sergeant Shane O’Connell are expected to be the final witnesses on Friday, ahead of Ms McMurdo making her closing remarks.
Australian Associated Press