Sergeant Till, 31, was a specialist explosive ordnance disposal officer from the Holsworthy-based Incident Response Regiment in Sydney.
He was killed on March 19, 2009 while trying to defuse an improvised explosive device (IED) in Oruzgan province, Afghanistan.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
Vice-chief of the Australian Defence Force, Lieutenant General David Hurley, said Sergeant Till set an initial charge on the device before detonating it from behind the safety of his vehicle.
He then went to inspect the results, got some tools, and returned to the bomb to keep working on it.
"Sergeant Till was kneeling next to the main charge when it detonated, killing him instantly," General Hurley told reporters in Canberra on Thursday.
"The inquiring officer found there was insufficient evidence to determined what initiated the detonation."
