Defence, like its minister Marise Payne, is refusing to reveal what part Australian aircraft played in an incident in Syria in which coalition aircraft inadvertently bombed Syrian troops, killing more than 60 soldiers.
Defence said the US-led coalition would review the incident thoroughly and Australia would co-operate fully.
"In order to maintain the integrity of this review, Defence will not provide any further details at this time," it said on Tuesday.
In the operation, coalition aircraft attacked what they thought were Islamic State vehicles south of the town of Dayr Az Zawr in eastern Syria on Saturday.
As the strike unfolded, Russian officials contacted the Coalition Air and Space Operations Centre in Qatar to say they were hitting the Syrian military.
The strike was halted. Russia claimed it killed 62 soldiers and wounded another 100. Reports from Syria suggest the attack was carried out by two US F-16s and a pair of US A-10 ground attack aircraft.
The Australian Department of Defence subsequently confirmed that Australian aircraft participated in this operation.
But it's declined to say just what aircraft were involved and what part they played.
The RAAF air task group in the Middle East comprises six F/A-18 Hornet multi-role fighters, a KC-30A tanker aircraft and an E-7A Wedgetail airborne early warning and control aircraft.
They fly from bases in the United Arab Emirates and conduct missions over Iraq and Syria.
RAAF chief Air Marshal Leo Davies said the vast majority of Australian operations were over Iraq.
"It is a very small proportion of missions that goes across the border," he told reporters in an interview last week.
Australia conducted the first mission over Iraq in October 2014 and Syria in September 2015. Over the last two years, missions have evolved as Islamic State forces have adjusted their tactics.
Initially, IS forces moved openly in large groups but speedily learned to minimise the risk of air attack by travelling in small units. More recently, improved intelligence from the battlefield has allowed an increase in attacks on IS forces in their defensive positions.
