The 40-year-old special forces veteran was on his seventh combat tour and leading a combined force of Australian and Afghan troops in a raid targeting a suspected Taliban commander in the Chorah Valley of central Afghanistan.

Deployed by helicopters while under heavy attack, two of the patrol's scouts were quickly pinned down by a machinegun firing from about 50m away.

Sergeant Diddams repeatedly left cover, moving out into the open to fire his rifle in the hope of taking pressure off the two trapped men. After being hit by a bullet that passed through the gap between two plates of his body armour, he was quickly treated by the patrol medic and airlifted to hospital, but later died.