Defence yesterday released a comprehensive, but partly censored, report into the incident, which said nothing could have prevented the shooting.

Defence force vice-chief Air Marshal Mark Binskin said Lance Corporal Jones' death on May 30 continued to haunt his colleagues.

''I will be frank - the death of Lance Corporal Jones was a cowardly act of murder,'' Air Marshal Binskin told reporters in Canberra. ''This murder was distressing for Lance Corporal Jones' family, his colleagues and Australians more broadly.''

Lance Corporal Jones (pictured) was a cook attached to the Mentoring Task Force 2 (MTF2) and serving at Patrol Base Mashal, a joint Australian and Afghan army base.

The report said Afghan soldier Shafied Ullah shot Lance Corporal Jones from a tower, as the Australian used the latrines below. He fired three or four rounds from his M16 into the soldier, who was unarmed and not wearing body armour, severely wounding him.

Air Marshal Binskin said body armour would not have saved the soldier. ''His wounds were outside the coverage of standard body armour. And he was in compliance with the force protection measures for the patrol base.''

Lance Corporal Jones was rushed to a medical facility at Tarin Kowt, but died of his injuries hours later. Ullah fled the base.

''Shafied Ullah fired from an elevated position which provided protection from return fire,'' the report found. Ullah had been on the base for nine days, and with the Afghan army for four months.

Coalition forces killed Ullah on June 19. Defence said he was shot and killed at a house in Khost after he threatened coalition forces with a pistol as they tried to detain him.

But Defence said nothing could have prevented the incident, and there had been no prior indications or warnings that Ullah was a specific threat.

''The inquiry is of the opinion that the excessive wearing of PPE (personal protective equipment) and carriage of weapons while inside a secure COP [compound] may be counterproductive to the relationship between AS [Australian] and ANA [Afghanistan National Army], and in turn negatively impact on force protection,'' the report said.

Air Marshal Binskin agreed. ''We will never know why Shafied Ullah shot Lance Corporal Jones,'' he said. ''There was no evidence to indicate that he had prior links to insurgents, was influenced by anyone else, or had made any preparations to commit such a violent act against Australian forces.''

He said there was a ''strong and workable relationship between Australian and Afghan forces at Patrol Base Mashal'', but a ''constant but manageable tension'' remained, mostly because of cultural differences.

These would not be aided by increasing defensive security on base.

Also released yesterday were brief reports on the deaths of Sergeants Todd Langley and Brett Wood, who were also killed in Afghanistan last year.

Sergeant Wood, a member of a Special Operations Task Group force, was killed on May 23 last year when an improvised explosive device laid by Afghan insurgents exploded. Two fellow commandos were wounded.

Sergeant Langley, an Australian commando also serving with the Special Operations Task Group, was struck by gunfire during a battle with insurgents on July 4 last year, while he was helping a fellow soldier who was wounded.

Defence said it would not release full reports on the deaths out of respect for the soldiers' families' privacy.