The Victorian Government has intervened on the side of the Office of Police Integrity in its high-stakes battle to be allowed to publish a report critical of The Australian newspaper and reporter Cameron Stewart.

The battle over the report, which The Australian wants to suppress, was scheduled to begin in the Federal Court this morning, but the hearing has been adjourned to next Thursday because of issues to do with the intervention of the Victorian Attorney General Rob Hulls.

Hulls has joined the OPI in arguing that the Federal Court does not have the power to stand between the state parliament and its officer, Director of the Office of Police Integrity Michael Strong.

The intervention is significant in terms of the precedent the case will now set, but also because it shows the Brumby Government is not abandoning its embattled anti-corruption agency despite the sustained attack by elements of the police force and The Australian.

This follows yesterday’s claim by Strong that The Australian was using its news pages to campaign against the OPI in the lead-up to the court battle. The Australian has published a series of stories, the latest just today, that have been sourced from former Assistant Commissioner Noel Ashby’s legal team, alleging the OPI has behaved wrongly and even corruptly.

All state and territory attorneys general were invited to join the action on the issue of Federal Court powers, but so far only the Victorian Government has decided to do so.

Meanwhile, documents now available on the Federal Court file show that Stewart told the News Limited legal team last March that publication of the OPI report would be “likely to cause him reputational loss.”

The report relates to Stewart’s scoop of August last year in which he published details of a joint federal and state anti-terrorism operation on the very day that raids were conducted and suspects arrested.

The investigation by the OPI and its federal counterpart, the Australian Commission for Law Enforcement Integrity, began straight away. A Victorian police officer has been stood down, suspected of being Stewart’s source.

Meanwhile the OPI has said it wishes to brief both state and federal prosecuting authorities about the commission of a serious criminal offence during the research for Stewart’s scoop, with the key piece of evidence being a record of interview with Stewart.

The Australian is claiming the OPI’s investigation was invalid because it did not have the power to enter into a joint investigation, and because it did not have the power to make findings about the Australian or its employees.

The case is now due to begin next Thursday.