It is so unlikely anyone will be charged or held to account over the Lawyer X scandal that a top investigator threatened to quit unless his own probe into the matter is wound up.

Special Investigator Geoffrey Nettle said continuing with an investigation into the use of barrister Nicola Gobbo as a police source during Victoria’s gangland war would be a “waste of time”.

He had major issues accessing key documents over the past 18 months, according to a report tabled in Victorian parliament on Wednesday.

The Office of the Special Investigator was set up to see if charges could be laid against Ms Gobbo or members of Victoria Police, however it does not have the power to do without approval from Director of Public Prosecutions Kerri Judd.

Ms Judd queried if there was enough evidence to file charges against several people and whether it was in the public’s interest to do so because any convictions would likely lead to a non-custodial sentence, according to Mr Nettle.

“I no longer think it is realistic to suppose the director could be persuaded to approve any charge of relevant offence,” he said in the report.

“I consider that there is no longer any point in (the special investigator’s office) persisting with investigating and determining whether there is sufficient evidence to establish the commission of relevant offences.”

He said any future probe would be “a waste of time and resources” and suggested it be wound up.

“I consider it to be pointless for (the office) to continue,” Mr Nettle said.

The office was established in early 2021 following a multi-million dollar royal commission into the Gobbo affair.

It has so far received more than $25 million in funding from the state government but that’s set to run out on June 30.

Some $39.5 million was allocated to the royal commission and it ultimately cost Victoria Police $64 million.

Mr Nettle offered to resign if the work of his office continues “so that someone whose views more closely accord to the Director’s position may be appointed in my place”.

Letters from Ms Judd were included in the report and in one she explained that her office was unable to start a prosecution unless satisfied there would be a reasonable likelihood of conviction.

She noted that by the time a case made it to trial it would be about 15 to 25 after the events occurred and offences such as misconduct in public office are difficult to approve beyond reasonable doubt.

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.

Premier Daniel Andrews said he was yet to read the report but it was up to the Ms Judd – not the government – to decide whether charges are laid.

“That is a really important part of our system,” he told reporters at parliament on Wednesday.

“(It) doesn’t mean everybody necessarily agrees with the decisions that the director … makes. Quite often they’ll be people who don’t think that’s done well.

“That’s part of the back and forth of public policy, I suppose, and the administration of justice.”

Attorney-General Jaclyn Symes also stressed the importance of public prosecutors acting independently to government or government bodies and reaffirmed a commitment to long-lasting cultural change in the criminal justice system.

A spokesman for the Office of Public Prosecution confirmed a copy of the report had been received and it would respond in due course.

– AAP