A former elite soldier has told a court he felt "threatened" that if he did not cooperate with newspapers being sued by Ben Roberts-Smith, he would instead be subpoenaed as a hostile witness.
War veteran Mr Roberts-Smith claims articles published in The Sydney Morning Herald, The Age and The Canberra Times in 2018 falsely accused him of unlawful killings, bullying and domestic violence.
A former Special Air Service Regiment (SAS) soldier, who was in Mr Roberts-Smith's patrol in Afghanistan in 2012, on Monday agreed under cross-examination he was "apprehensive" about being called as a witness by publisher Nine Entertainment.
Codenamed Person 56, the witness recalled a September 2012 mission in the village of Darwan mentioned in the articles.
It was alleged in the stories that an unarmed, handcuffed Afghan farmer named Ali Jan was kicked over a cliff by Mr Roberts-Smith and then executed after falling into a creek bed, which Mr Roberts-Smith denies.
The Federal Court heard Person 56 previously told Nine's lawyers he did not intend to speak to any party or give evidence because he lived with a mental health condition and his wife was sick.
His lawyer fielded communications from Nine in March last year from which he understood he would not be called as a witness.
But the court heard that changed in August, when a Nine solicitor wrote to Person 56's barrister and said they had become aware of an allegation Person 56 was involved in the execution of two prisoners with Mr Roberts-Smith during a separate November 2012 mission in the village of Fasil.
Under cross-examination, Person 56 agreed it was his understanding that if he did not speak to Nine's lawyers about Darwan and "help them get what they need for their case against Mr Roberts-Smith", he would be subpoenaed as a hostile witness and asked questions about Fasil.
"You considered that to be a threat?" barrister Arthur Moses SC asked.
"Yes," Person 56 replied.
The court has heard of a "deal" or "arrangement" between Nine and Person 56 that if he gave evidence about Darwan, they would not oppose any objection by him against answering questions about Fasil.
Person 56 had meetings with Nine's team in October and signed a statement at the end of that month, at a time when he was battling anxiety.
"And this approach by the respondents [Nine] had an impact on your mental health?" Mr Moses asked.
"Yes," the witness replied.
"Is it fair to say you signed the statement because you wanted to get the respondents off your back?" Mr Moses asked.
"Yes," Person 56 said.
Person 56 earlier told the court that during the Darwan mission, he helped search compounds and about half an hour before they were extracted via helicopter, he left the final compound with an interpreter before proceeding to a vegetated area on the other side of a creek bed.
He said there was "no significant embankment" at the creek bed, rather, a "knee-high" area, and he did not hear any "engagements" or enemy contact, nor any radio calls about any engagements.
The court heard when the soldiers returned to camp, Person 56 heard another member of his patrol, either Person 4 or Person 11, say words to the effect of "an individual had been kicked off a cliff and subsequently shot".
Person 56 objected to giving evidence about Fasil on the grounds of potential self-incrimination and, following a legal debate, was not compelled to do so.
The trial, before Justice Anthony Besanko, continues.
