The ACT Supreme Court has rejected an appeal by the Commonwealth to update secret evidence in its prosecution of whistleblower Bernard Collaery.
The attorney-general had sought to update evidence - which Collaery and his lawyers are unable to see, and was first taken two years ago - by arguing time had rendered parts of it inaccurate.
But Justice David Mossop ruled that updating the evidence would go beyond the remit given to him by the Court of Appeal, which sent the matter back to him after ruling that the case should be held in open court.
The Commonwealth had pushed for the case to be heard in secret on national security grounds, which Justice Mossop initially agreed to.
But his decision was overturned by the Court of Appeal which ruled that public confidence in the justice system springs from an open court process and deters political prosecutions.
The Court of Appeal ruled that Justice Mossop had put too much emphasis on national security and too little on administering justice when he originally ruled the case could be held in secret.
It said an open court stands as a bulwark against political prosecutions by allowing public scrutiny.
But the Court of Appeal sent the case back to Justice Mossop to deal with the issue of evidence only the judge could see.
Following his move to disallow updates to the secret evidence, Justice Mossop will now deal with whether evidence Collaery does not have access to will be allowed to be used against him at trial.
The parties are due back in court on Wednesday morning.
The ruling is a small win for Collaery but the attorney-general can still choose to make a fresh application for more restrictive orders on the basis of changes to the current circumstances.
The case has already been appealed to the High Court as the Commonwealth seeks to have part of the Court of Appeal judgment - which found secret trials diminished public trust in the justice system - redacted from the public.
Collaery is accused of unlawfully sharing classified information about the alleged bugging operation of the East Timor prime minister by Australian officials in 2004.
Australian Associated Press