A young soldier who survived combat in Afghanistan died from a prescription drug overdose after falling victim to Australia’s disjointed health system, inquest findings suggest.

Matthew Neil Hardy Tonkin originally developed PTSD during his service in the army, where his best friend was killed by an Afghan defector.

A rifleman in the Royal Australian Infantry, Mr Tonkin was also the first responder at two separate blasts from improvised explosive devices that blew off the legs of Australian soldiers, including another close friend.

A WA state inquest heard that a year later, between August and December 2013, he had overdosed four times, and on each occasion was treated at the local defence health clinic in Queensland where he was then stationed.