A British Army soldier may have been killed by friendly fire in Afghanistan, an inquest has heard.
Rifleman Stuart Nash was hit by a 7.62mm round fired from a British machine gun as he lay on the rooftop of a compound in southern Helmand. The 21-year-old Australian, who was serving with 1st Battalion The Rifles, died from a single gunshot wound to the chest.
He was taking part in an operation to clear insurgents out of the district of Nad-e-Ali on December 17 2008, the inquest in Trowbridge, Wiltshire heard.
Appalling weather and subsequent communication problems made the mission more challenging.
Rifleman Nash was part of a squad giving suppressive fire upon an insurgent target when he was hit. The inquest heard evidence the soldier was killed by a type of bullet used in British-issue GPMG machine guns.
Two armoured vehicles, which were giving support to the mission, were positioned to the east of Rifleman Nash's compound armed with GPMGs. They were bogged down in mud and under heavy fire themselves and were returning fire when Rifleman Nash was killed.
The initial Army investigation examined whether the soldier could have been killed by a round fired from one of these vehicles - an incident known as a "blue on blue".
Ballistic expert Dr Andreas De Villiers Horne ruled out the possibility the fatal shot could have been fired from an AK47 or sniper rifle favoured by insurgents. He examined 20 GPMG barrels taken from the armoured vehicle platoon and found it was "very unlikely" any of these fired the fatal shot.
However, Dr De Villiers Horne said it was possible it could have come from an unknown weapon carried by the insurgent forces. Dr De Villiers Horne said: "I would be careful to conclude that the ammunition was fired by Nato forces. It is not unusual in the heat of battle for ammunition to be lost."
David Ridley, coroner for Wiltshire and Swindon, said he could not be sure that Rifleman Nash had been killed by enemy forces and therefore could not record a verdict of unlawful killing while on active service. He recorded a narrative verdict.