KEY POINTS:
- The US warned Australia it could apply the Leahy Laws over alleged war crimes in Afghanistan.
- The laws prevent US troops from assisting military units who have violated human rights.
- The Brereton Report uncovered evidence of 39 murders committed by Australian troops in Afghanistan.
Australia was warned the US could restrict engagement with Australian forces over credible allegations they committed war crimes in Afghanistan.
But Senate estimates has revealed Defence chief Angus Campbell did not pass on the warning, which he received from the US embassy in Canberra, to either the former or current minister.
The 2020 Brereton Report uncovered credible evidence of widespread war crimes committed by Australian special forces in Afghanistan, including 39 murders.
General Campbell received a letter from a US defence attache soon after its release, warning the allegations could trigger the Leahy Laws - preventing US armed forces from working with or assisting troops that had violated human rights with impunity.
General Campbell told the committee that would have applied to the SAS regiment and special operations command embroiled in the Brereton Report.
Angus Campbell did not pass the warning on to his ministers.
"There's a difference between 'may' and 'does' ... [Mr Marles] does not know what I am telling you here," he said.
Independent senator Jacqui Lambie said both the ministers and public should have been informed about what she labelled "a threat".
"You have crossed the line," she told the general.
The US does not publicly comment on its application of the laws, although media reports suggest they have been imposed on military units from a handful of countries.
General Campbell confirmed no Australian troops were currently subject to restrictions, but conceded there was a "precautionary period where we looked at our arrangements" after the release of the Brereton Report.
And he did reveal one Australian Defence Force member had been moved over concerns that "Leahy Law issues may emerge".
General Campbell rejected suggestions from Greens senator David Shoebridge that his decision not to disclose the warning amounted to "a gross problem of a lack of transparency in our military"
"That is not the truth."
