It is so unlikely anyone will be charged over the Lawyer X scandal that a top investigator has threatened to quit if his own probe into the affair is not shut down.
Special investigator Geoffrey Nettle said the continuation of his probe into the use of barrister Nicola Gobbo as a police source during Victoria's gangland war would be a "waste of time" because of constant rejections by Director of Public Prosecutions Kerri Judd.
The Office of the Special Investigator was set up to examine if charges could be laid against Ms Gobbo or Victoria Police members, but it does not have the power to do so without approval from Ms Judd.
Victoria's chief prosecutor queried if there was enough evidence to file charges against several people and whether it would be in the public interest because any convictions would likely lead to non-custodial sentences.
"I no longer think it is realistic to suppose the director could be persuaded to approve any charge of relevant offence," Mr Nettle wrote in his report, tabled in parliament on Wednesday.
In one instance, Ms Judd rejected a recommendation for charges to be laid against five people after the special investigator compiled more than 5000 pages of admissible evidence, hours of audio recordings and multiple witness statements.
The investigator refocused on eight matters as the next strongest cases and settled on pursuing three, with plans to deliver an evidence brief for at least one by the end of this year.
But Mr Nettle wrote to Attorney-General Jaclyn Symes in May to declare the chances of Ms Judd approving any charges "were now effectively nil", rendering any future probes "a waste of time and resources".
In letters included in the report, Ms Judd explained her office was unable to start a prosecution unless she was satisfied there was a reasonable likelihood of conviction.
She noted that by the time a case made it to trial it would be at least 15 years since the events occurred and offences such as misconduct in public office were difficult to prove beyond reasonable doubt.
Ms Judd also expressed concern police would justify their actions on public interest grounds.
But her arguments were branded offensive, displeasing and disappointing in various responses from Mr Nettle.
He also complained about major issues in accessing key documents over the past 18 months.
Mr Nettle offered to resign if the work of his office continued, allowing someone to be appointed who had views more closely aligned with prosecutors.
The special investigator's office was established in early 2021 following a royal commission into the Gobbo affair.
It has received more than $25 million in state government funding, but that money runs out on June 30.
Premier Daniel Andrews said he was yet to read the investigator's report, but it was up to Ms Judd to decide whether charges were laid.
Ms Symes reaffirmed the government's commitment to cultural change in the criminal justice system when asked if the investigator's office would be wound up.
Shadow attorney-general Michael O'Brien said the government should give the special investigator the same powers as Victoria's corruption watchdog to unilaterally bring charges.
"It's inconceivable that after all the scandal of Lawyer X - the perversion of the course of justice, the dodgy dealings between a rotten lawyer and crooked cops - no one gets charged," he said.
Ms Gobbo was a popular gangland lawyer in Melbourne during the early 2000s while also acting as a police informant.
A royal commission found her dual role could have affected more than 1000 convictions.
She represented high-profile figures including Tony Mokbel and Faruk Orman, who have both since had their convictions overturned.
A spokesman for the Office of Public Prosecutions confirmed it would respond to the report in due course.
Victoria Police declined to comment.
