Liberal frontbencher Andrew Hastie has sounded a warning after Ben Roberts-Smith's partner labelled him a 'traitor' in a since-deleted comment.
The saga unfolded after Hastie, a former SAS soldier, shared a photo of him and his young family attending an ANZAC Day service in Perth on Instagram.
'Remembering the fallen, honouring our veterans and ADF, a responsibility for all Australians, young and old. Lest we forget,' Hastie captioned the photo.
'Yeah you're a traitor,' Sarah Matulin wrote.
Roberts-Smith's lawyer Karen Espiner told the Sydney Morning Herald that the comment 'was a mistake' and was not done with Roberts-Smith's knowledge.
Appearing on Sky News on Tuesday morning, Hastie remained tight-lipped on the fallout given ongoing legal proceedings involving his former SAS colleague.
The MP appeared as a witness in the Federal Court during Roberts‑Smith's failed defamation case and said it remained possible he could be called again.
'It is what it is, and I really have nothing to add to it. Life goes on,' Hastie said. 'I'm here with you this morning and keen to talk about more substantive issues.'
Andrew Hastie (pictured) said 'it is what it is' in response to the comments by Ms Matulin
The Liberal MP (pictured) served alongside Ben Roberts-Smith in Afghanistan
Pressed on whether he regretted anything he had said or done in relation to the Ben Roberts‑Smith case, Hastie gave a cautious response.
'I've been very careful about what I've said when I've had to give testimony, I've done it under oath, and again, that's all I have to say,' he said.
'I'm just very cautious given that a fair trial, the presumption of innocence and a few other legal principles are at stake here.
'I appeared as a witness in the Federal Court in the civil case, and there's a possibility I may do so as well in the trial ahead, so I'm very cautious here.'
Hastie was asked whether he was disappointed or shocked by the comment.
'Again, it is what it is. It's public life, and we just keep going. It's a new day - dawn here in Perth,' he said. 'I married really well. My wife loves me, my kids love me.
'In the end, family is what matters to me… that's what I take courage in.'
Hastie warned more broadly about the dangers of inflamed rhetoric online.
Sarah Matulin (right) has deleted a comment calling Andrew Hastie a 'traitor' on social media
'Social media is bringing out a lot of lies… an inclination towards violent language, which could be violent action in real time,' he continued.
'People just need to dial it back.'
Roberts-Smith is alleged to have committed five counts of 'war crime - murder' allegedly committed while serving with the Special Air Service Regiment in Afghanistan between 2009 and 2012.
He is accused of shooting dead one unarmed detainee not taking part in hostilities, taking part in the unlawful killing of a another, and ordering subordinates to execute three more. Roberts-Smith has consistently denied the allegations.
It is currently unknown whether Hastie will be called on to give evidence during the NSW Supreme Court criminal trial.
The MP issued a statement to media two days after Roberts-Smith's arrest.
'In 2022, I was one of 21 SAS veterans of the war in Afghanistan subpoenaed as a witness in the defamation action brought by Ben Roberts-Smith against Nine Media.
'I gave testimony under oath, as required by law. Mr Roberts-Smith is now facing criminal charges in relation to this operational mission, so it is possible that I will be called as a witness to this trial.
Hastie continued: 'I urge every Australian to respect the rule of law, the criminal justice system, and the accused's right to a presumption of innocence and a fair trial.
'Therefore I will not prejudice this trial by making any further comment.'