Ben Roberts-Smith defamation case delayed as Fairfax lawyers seek to introduce new evidence

The federal government has again stymied the public airing of evidence in the Ben Roberts-Smith defamation trial, creating further delays and prompting a federal court judge to express frustration.

Roberts-Smith, a special forces veteran, is suing Fairfax, now Nine Entertainment, in the federal court for a series of articles he alleges defamed him by suggesting he committed war crimes while serving in Afghanistan.

The attorney general, Christian Porter, previously intervened in the case, invoking national security laws to keep aspects of the case secret. The move sparked concern among Australian transparency campaigners and journalists.

On Wednesday lawyers for Fairfax sought to amend their defence and introduce outlines of new evidence to the court. But the commonwealth quickly raised national security concerns.

Related: Secrecy in Ben Roberts-Smith defamation case alarms transparency campaigners

Peter Melican, of the Australian government solicitor’s office, asked that no reference to the new evidence be made in open court until the government had a chance to review it.

“I am informed the attorney – or the commonwealth, perhaps more accurately – has concerns that some of that material does include national security information,” Melican said.

“The commonwealth respectfully requests that there be no reference to the content of those outlines of evidence until it has had an opportunity to review that material and make an application to the extent that it needs to.”

That prompted Justice Anthony Besanko to express frustration.

“I don’t know why this wasn’t attended to [earlier],” he said. “Bearing in mind the intervention of the commonwealth in these proceedings, why it wouldn’t have been perfectly obvious to the parties and the commonwealth that there was a need to scrutinise all of the material that might possibly come before the court or be referred to before the court?”

Melican said the commonwealth had previously asked lawyers representing Fairfax and Roberts-Smith to notify it if they intended to introduce evidence that may raise national security concerns.

That notice had only received by the commonwealth on Wednesday morning, he said.

He asked that the evidence be suppressed for five days until the commonwealth had a chance to review it. Besanko rejected that proposal.

But the court did adjourn for five days to give the commonwealth a chance to review the evidence and make any arguments it wished to about the national security implications.

Bruce McClintock SC, representing Roberts-Smith, said the commonwealth had had access to the material for months. It had been given ample time to raise national security concerns, McClintock said.

“Every five days we lose means that my client is further away from having this matter heard, and it’s fundamentally important to him,” he said.

The case will return to the federal court on Tuesday.

This month the court ruled that the trial would need to be held in person, rather than via weblink, due to the sensitive nature of the evidence. That led the judge to vacate the original trial date of 15 June.

“In my opinion, an in-person trial is necessary for two independent reasons,” Besanko said at the time. “The first reason is that such a trial is necessary to deal with the issues relating to, or arising from, the disclosure of national security information.

“The second reason is that this is a trial where the credibility or reliability of the key witnesses may well be crucial in circumstances where the alleged imputations arising from the matters complained of are, as I have said, very serious indeed.”