The letter sent this week to people involved in the inquiry was signed by IBAC deputy commissioner David Wolf and informed them that they were “no longer bound by the terms of the confidentiality notice previously served on you”.

“On this occasion,given Operation Richmond is nearing completion,IBAC does not intend to issue a new confidentiality notice to you as it’s no longer considered necessary to restrict disclosure of the restricted matters in respect of this investigation.”

The disclosure of the probe’s imminent conclusion means a “special report” will likely be published this year,as the Andrews government seeks re-election.

Sources with knowledge of the investigation who are not authorised to comment publicly have confirmed that one aspect of the IBAC investigation involved scrutiny of the Premier’s actions. The commission has also questioned whether Mr Andrews was transparent in advising the Victorian public or his cabinet or caucus colleagues about his interventions in dealings with the United Firefighters Union.

Last October,Mr Andrews declined to say whether he had been contacted by IBAC,telling reporters to direct their questions to the corruption agency. The removal of the confidentiality obligation will put pressure on the Premier to detail any dealings he has had with IBAC. However,the Premier could still rely on a convention to remain silent when an active investigation is under way.

The Court of Appeal decision could allow witnesses – including political enemies of the Premier – to disclose details of the inquiry and their dealings with it.

The court found the gag orders were written in a manner that did not sufficiently specify the “restricted matters” in an IBAC probe. As a result,IBAC was forced to revoke its confidentiality notices in several investigations.

For those investigations that are still in evidence-gathering phase,the corruption agency reissued new notices. But parties involved in Operation Richmond were not reissued notices because the investigation is at such an advanced stage.

IBAC chief executive Marlo Baragwanath said the commission was “not above scrutiny” and “accepts the decision of the Court of Appeal”

“Acting on the Court of Appeal decision,IBAC has reviewed the form of confidentiality notices it issues to ensure they address the technical aspects raised by the Court of Appeal and provide more details about the relevant restricted matter,” Ms Baragwanath said.

“IBAC has also contacted people who had received confidentiality notices to inform them of this issue,and where necessary,reissued the confidentiality notice or advised people that they are no longer bound by the terms of confidentiality notice”.

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