Some serving defence force members and veterans may be unable to testify at a royal commission due to federal laws governing operationally sensitive and intelligence information.
The Royal Commission into Defence and Veterans Suicide began the fifth day of its latest round of hearings on Friday in Australia's largest army city, Townsville.
Ahead of Australian Defence Force Chief General Angus Campbell resuming his testimony, the commissioners heard from Stephen Free SC, representing the Commonwealth.
Some ADF members who want to give evidence could risk breaking the law due to "legislative impediments" around operational matters, but Mr Free said the Commonwealth was committed to overcoming these limitations in time.
Commission chair Nick Kaldas told Mr Free "a cynical mind would think there's been tardiness on behalf of the Commonwealth", noting the commission had been waiting nine months for an answer on the issue.
"I know it's a long and arduous process and no guarantee of success, but if you've reached a point where you think the legislation is simply not rational ... surely the Commonwealth has an obligation to do something about the legislation that is a problem," he said.
Asked about this issue, General Campbell said he believed the inquiry was about "human interaction", not operation matters, and that evidence did not "require a conversation about tactics."
"I am very confident they can be heard," he said.
The rest of Friday morning's session focussed on unacceptable behaviour in the ADF, how the army manages negative incidents and the case of an army member who took their own life, referred to as Person B.
After B died, his mother - referred to as Person A - alleged B was bullied by an officer, Person C, and that this led to the death of her son.
She raised concerns with the ADF and Army about unacceptable behaviour by C dating back some years.
But the allegations were not known to an inquiry into the death of B.
General Campbell, who recalled meeting twice with A, instructed the Inspector-General of the Australian Defence Force in 2017 to examine the incident management system to identify whether the Army had any knowledge of A's core allegation about the behaviour of C.
"I wanted to know more broadly whether there was anything else in the Army incident management system with regard to Person C," Gen Campbell told the inquiry.
Counsel Assisting, Peter Gray QC, asked the general about the outcome of that process.
"I was advised that there was a process that ultimately led to a notice to show cause for continuance or cessation of service of Person C, with regard to a longitudinal pattern of behaviour not related to the issues raised by Person A, and that subsequently, Person C ceased to service in the ADF."
Later, when pressed by Mr Gray, Gen Campbell noted the command responsibility and welfare of ADF members rested with him.
"Does that mean ... minimising of physical, psychological and mental harm from service? Where is the accountability and responsibility for minimising psychological and social harm from service located?" Mr Gray asked.
"It is Command. It is my responsibility, my accountability ... I am accountable and commanders are accountable," General Campbell replied.
General Campbell is due to conclude his evidence to the commission on Friday.
