When Nine newspapers first announced to the Federal Court the 30 witnesses it was likely to call in its blockbuster defamation case against Ben Roberts-Smith, one familiar name stood out.

Near the bottom of that list, which included the pseudonyms of 20 serving and former Special Air Service Regiment members, was another ex-soldier: Andrew Hastie, federal member of parliament.

Hastie, who had served as a troop commander with the SAS in Afghanistan, was the only one of his erstwhile comrades who gave evidence - other than Roberts-Smith - who was publicly identified.

Nine months before Hastie stepped into the witness box, Roberts-Smith's senior counsel Bruce McClintock had downplayed the significance of whatever the politician intended to tell the court.

'Mr Hastie has long been a commentator for [Nine] and anti-my client, if I could put it like that,' the barrister said in June 2021.

Five months later, it was revealed that Nine had undertaken to pay for legal advice and representation for Hastie to appear in an unrelated defamation case involving the publisher.

When Hastie appeared on the Federal Court stand in March the following year, he was asked if he disliked Roberts-Smith, who Nine newspapers had accused of murdering unarmed Afghans.

'I don't dislike Mr Roberts-Smith at all,' Hastie said of the Victoria Cross recipient. 'I pity Mr Roberts-Smith. I pity this whole process. I don't want to be here.'

The Liberal MP repeatedly suggested he was a reluctant witness who was testifying because he had been subpoenaed to give evidence for Nine. 

'Before I gave evidence here, I rang my father and I asked him to pray with me,' Hastie said. 'And he prayed for Mr Roberts-Smith as well.' 

Hastie might not have wanted to be there, but the deeply religious father of three had helped the newspaper investigation that eventually led to Roberts-Smith's downfall.

Reporter Nick McKenzie, from The Age, and freelance journalist Chris Masters authored the 2018 newspaper reports that originally accused Australia's most decorated living soldier of war crimes. 

Under cross-examination by Roberts-Smith's barrister Arthur Moses SC, Hastie was asked if he had come to court to support McKenzie and Masters in defending themselves.

'Yes,' he said. 'I have been subpoenaed by the court to appear and give evidence to that effect, but it's not something I take any pleasure in, Mr Moses.'

Hastie defended his decision to speak with the journalists about Roberts-Smith, stating 'the system' had failed to expose war crimes allegations and it was 'up to the fourth estate to do the job'.

He agreed McKenzie was a 'personal acquaintance' and said Masters was someone he knew 'very well' from contributing to his 2017 book No Front Line. Pushed on his relationship with McKenzie, Hastie conceded they were 'friends - friends, of a kind'.

Hastie denied having a 'symbiotic', 'mutually beneficial' or co-dependent relationship with McKenzie but said he held him in 'high regard'. 

'Professionally, I would say he's a journalist I have worked with over the last five years,' Hastie told Moses. 'But we wouldn't go on holidays if that's what you're suggesting.'

Hastie was at that time assistant minister for defence and his evidence-in-chief largely related to a 2012 mission in which Roberts-Smith and a junior soldier dubbed Person 66 took part. 

Since 2018, Hastie had been speaking to McKenzie about Roberts-Smith off the record, he told the court.

Justice Anthony Besanko ultimately found on the balance of probabilities in June 2023 that Roberts-Smith had murdered Afghan detainees, in a major win for Nine.

The extent of Hastie's role in that victory is laid out in McKenzie's book Crossing the Line: The Inside Story of Murder, Lies and a Fallen Hero, in which he is named 104 times.

On April 7, Roberts-Smith was charged with five counts of murdering Afghan detainees between 2009 and 2012 - allegations he vehemently denies. 

Since then, Hastie has been cautious about what he has said about Roberts-Smith, confirming he may be called to give evidence if the case ever makes it to trial.

Two days after the charges were laid, Hastie issued a statement describing himself as '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'.

'As a qualified member of the SAS, I was present on one of the operational missions in 2012 that was examined by the Federal Court,' Hastie said. '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.

'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.'

McKenzie names Hastie in the author's note of his June 2023 book about Roberts-Smith as one of the sources he interviewed 'at length or on multiple occasions'.

He introduces Hastie into the narrative in a chapter titled 'Pastor's Son, Fighter, Politician' with a flashback of him waking in his Perth bed in 2014, 'straining to see through the darkness'.

'It had happened again,' McKenzie wrote. 'Another dream where he was back in Afghanistan surrounded by chaos, flashes of a dead Australian soldier, faces of his comrades and voices whispering about covering up the death.'

As Hastie described in his Federal Court testimony, that was one of two types of recurring dreams the 32-year-old 'blond-haired captain' had been having at the time.

'The other also involved Afghanistan, but it featured a face staring at his own: that of Ben Roberts-Smith,' McKenzie recounted.

Lying in bed, Hastie's 'mind drifted back to the image of the dead soldier' - a faceless Australian combatant who had been killed by friendly fire and whose death the SAS had covered up.

No such incident had occurred in Afghanistan, 'but Hastie figured the dream was the product of the lingering unease he now felt about the regiment he had striven so hard to join'.

Hastie had once held Roberts-Smith in high regard, encountering him at an Australian base in Afghanistan in June 2009 while commanding a troop of the 2nd Cavalry Regiment.

'He was wearing footy shorts, pistol on his hip,' Hastie said during the defamation case. 'You know, he looked a million dollars.'

Hastie won selection to the SAS in August 2010 and was briefly sent to Uruzgan Province in late 2012, and again in 2013 for a longer deployment. 

On that second trip, Hastie had begun 'encountering Australian special forces soldiers who seemed not just worn out, but damaged', according to McKenzie's book.

Hastie was concerned by 'excessive drinking' by SAS troopers, a potential loose interpretation of the rules of engagement, and success being measured by kill counts.

He was particularly disturbed by an incident in which one of his troopers had cut off the hands of a dead Taliban fighter to make it easier to fingerprint the slain insurgent.

Hastie left the Army in August 2015 and was elected as the member for Canning - south of Perth, where the SAS is based - the next month. According to McKenzie, the politician was soon getting calls from journalists about Roberts-Smith's conduct.

Hastie strongly supported the 2016-2020 Brereton Inquiry into war crimes allegedly committed by Australians in Afghanistan and criticised a toxic 'warrior' culture in special forces. 

McKenzie and Hastie first spoke by phone in January 2018, according to Hastie. As  McKenzie prepared to publish the stories which would accuse Roberts-Smith of being a war criminal, Hastie 'remained supportive'.

'I had begun to consider the conservative politician a friend,' he wrote in Crossing the Line. 

In May 2018, McKenzie confided in Hastie that his efforts to 'cast a light into the dark corners of his former regiment's history might have hit a wall'.

'You OK, mate?' Hastie asked the reporter in a phone call. After hanging up, Hastie sent McKenzie a biblical quote from 1 Corinthians: 'Be on your guard; stand firm in the faith; be courageous; be strong'.

McKenzie's interpretation of that text was, 'Hastie was urging me to keep going.'

Hastie was interviewed by McKenzie for a 60 Minutes story on the SAS and Roberts-Smith in 2019, in an appearance he accepted in the defamation trial portrayed him in 'a very positive light'.

As the defamation trial grew closer in April 2020 and Nine was fighting to protect SAS witness's identities, McKenzie wrote, 'the only known journalistic source was Andrew Hastie'.

When Hastie finally gave evidence, he testified: 'My ambition has been to preserve the SAS regiment and the way to do that is by coming clean on some of the mistakes of the last 15 years.'

McKenzie said Hastie 'felt emotion wash over him as he spoke'.

'He may not have directly witnessed a war crime, but he knew enough to know bad things had likely happened,' he wrote. 

'Hastie had done what he had set out to do: tell the truth, whatever the impact on his political career. 

'He had even gone in to bat for those less popular than politicians - he told the court that he reason he had spoken to me was that he believed journalists had played a vital role in the war crimes scandal.'

Roberts-Smith is next due to face court on June 2.