High Court puts off any decision on whether Australian spying details should be kept

The High Court has put off any decision on whether details of an alleged Australian spying operation in Timor-Leste should remain secret during a criminal trial.

Bernard Collaery, a barrister and former ACT attorney-general, is accused of conspiring to reveal classified information about Australian espionage in Timor-Leste — also known as East Timor — during sensitive oil and gas negotiations two decades ago.

The years-long case still has no trial date, as the parties battle over what evidence should be hidden from the public.

The Commonwealth argues that the Commonwealth should not share with Mr Collaery or his lawyers because of the dispute over two types of secret evidence: general prosecution evidence, which the Commonwealth says should not be heard in public.

The federal government has argued that the highly classified court-only material should not even be heard by a court.

Last month, ACT Supreme Court Justice David Mossop found that the court could get the evidence by appointing a special counsel who had access to the documents to advocate on Mr Collaery's behalf.

But at the High Court today, federal Solicitor-General Stephen Donaghue argued against that decision, saying the information must remain unaffected, even by a special counsel, to protect national security.

If this isn't stopped, the earlier ACT judgement could be released without the redactions we need, according to Donaghue.

The three High Court judges that were hearing the matter asked Mr Donaghue if he was simply asking for a stay.

Justice James Edelman, a judge, said the Commonwealth had failed to identify the ACT court's error.

Justice Edelman said that the ACT Chief Justice didn't make the orders you wanted.

The court was told by Donaghue that he was not asking it to plunge into the secret material, but instead to delay the publication of the ACT court's reasons until the separate issue of court-only material was resolved.

There have been years of hearings and appeals about how a court should handle the evidence involved in the case.

A year ago, the ACT Court of AppealACT Court of Appeal noted that disclosing some issues in the case could risk prejudicing national security.

The court expressed doubt that any significant risk would materialise and there was a very real risk to public confidence in the administration of justice if the evidence could not be publicly disclosed, the summary read.

The court's full judgement was not made public, because the Commonwealth said it wanted the High Court to rule on its publication.

The High Court justices suggested the federal government set aside the case until the matter of court-only evidence is resolved.

The case will now go to the ACT Supreme Court.

Mr Collaery's co-accused, known as Witness K, pleaded guilty last year and was given a three-month suspended sentence.