A corruption watchdog report into negotiations between a state government and firefighters union will remain secret, even after the union lost a bid to block its publication.
The United Firefighters Union and its secretary Peter Marshall took the Independent Broad-based Anti-corruption Commission to the Victorian Supreme Court over the Operation Richmond report.
The operation, launched in 2019, investigated the Victorian government's negotiations with the union over reforms to merge existing fire services into the new Fire Rescue Victoria.
IBAC had indicated the final report would be published by July 1 but the union and Mr Marshall filed a last-minute injunction application in May.
A hearing over the application was heard in closed court on June 24 when the contents of the report were discussed without media present.
The plaintiffs argued IBAC was relying on education and prevention functions as a reason to make the report public, which they said exceeded the limits of IBAC's powers.
But Supreme Court Justice Claire Harris on Friday dismissed the union and Mr Marshall's application, finding they did not establish any of the grounds of their legal challenge.
Lawyers for the union and Mr Marshall said they would need time to consider the ruling before deciding whether to appeal.
IBAC subsequently provided an undertaking to the court, confirming it would not transmit the report to parliament or publish it in any other way until the plaintiffs considered their appeal.
If they do not lodge an appeal or indicate their intention to appeal by 4pm on July 17, then IBAC will take steps to release the report.
It could still take some time before the report is in the public domain due to the provisions of the IBAC Act, the court was told.
Justice Harris formally dismissed the union and Mr Marshall's application and ordered them to pay IBAC's legal costs.
IBAC said it was pleased with Friday's outcome.
"Reporting to parliament and the public on IBAC's investigative findings is a crucial part of our role in exposing and preventing corruption and misconduct in Victoria," a spokesperson said in a statement.
"While IBAC remains committed to the release of the Operation Richmond special report, we will refrain from publication or providing further comment until the conclusion of the appeals period."
The identities of Mr Marshall and the union were originally protected under a pseudonym order, but they were unmasked on June 12 following a failed bid in the Victorian Court of Appeal.
The court determined Justice Harris had not made an error in rejecting their original pseudonym application on the grounds the information was already in the public domain.
