A special investigator tried to bring charges over Victoria’s gangland lawyer-turned-police informer scandal before he had any power to do so, the state’s prosecuting chief says.

Director of Public Prosecutions Kerri Judd has issued the latest salvo in what has become a public spat between her and special investigator Geoffrey Nettle.

Mr Nettle was appointed in 2021 to see if criminal cases could be made against Nicola Gobbo and Victoria Police officers following a royal commission into the gang wars using her as an informer on her clients.

On Wednesday, he tabled a report to parliament saying his office should be shut down or he will resign because Ms Judd had repeatedly rejected briefs of evidence for charges over the Lawyer X affair.

“All three prosecutions were refused on the basis that there were not reasonable prospects of conviction,” Ms Judd wrote in her response on Thursday, also tabled in parliament.

The prosecutions would have been made under the Special Investigator Act 2021, but when Mr Nettle first asked Ms Judd to authorise charges in October that year the act had not yet started and his office had no investigative powers, she said.

“As a consequence of the (Office of the Special Investigator) having no investigative powers, I was asked to consider authorising the proposed direct indictment primarily on the basis of redacted material publicly available on the royal commission’s website, much of which I considered would not have been admissible in a criminal trial,” she wrote.

“This is not a criticism of the OSI – it merely reflects the difficulties in preparing and assessing a potential prosecution in circumstances where the OSI did not yet have any investigative powers, but considered it was necessary to act with haste because of a risk the individual concerned would leave the jurisdiction.”

The first proper brief of evidence was submitted to her in November 2021 for perjury charges against the same person raised a month earlier.

Ms Judd wrote that she asked for more material on the case on December 1, 2021, and the special investigator said he would try to provide it.

“To date, I have not received further material in relation to that brief of evidence,” Thursday’s six-page response reads.

She said she never ruled out the prospect of authorising any future prosecution, and would consider any further briefs on their merits.

“My decisions in relation to these matters should be interpreted as nothing other than the results of careful and realistic assessments of the evidence,” Ms Judd wrote.

Premier Daniel Andrews said it wasn’t up to his government to decide whether anyone would be charged over the Gobbo affair, after she acted for several Melbourne gangland figures during the early 2000s while also a police informant.

“It’s the evidence, and a comprehensive brief of evidence, that should be the only factor,” he told reporters on Thursday.

Attorney-General Jaclyn Symes rebuffed a call from the opposition to give the special investigator’s office unilateral powers to lay charges.

“It is not appropriate for an investigative body to then decide whether they are the prosecutor as well,” she said.

– AAP