Australian hikers on the Kokoda Track in Papua New Guinea were mistaken in thinking they had stumbled upon the body of a World War II pilot, the Australian Defence Force (ADF) said Thursday.

What they actually found last week was not a corpse in a parachute harness caught in a tree but a mossy branch with an uncanny resemblance to a human form.

The Kokoda Track is a popular hiking trail for Australians and Japanese visiting the locations where their forces clashed in 1942. Beginning 50 kilometres east of Port Moresby, the PNG capital, the Kokoda Track runs for 96 kilometres through the rainforest of the Owen Stanley Range.

"While the location near Kagi is below a flight path that was commonly used by allied aircraft during World War II sorties, the find has been confirmed by ADF staff as a moss-covered branch," the ADF said in a statement. "It appears the branch has broken off the main tree and fallen across some vines which, from the ground, could have been confused with the body of an airman."

Tour guide David Collins, owner of Melbourne's No-Roads trekking company, had alerted authorities to what he thought was the body of a fallen soldier.

"It's swinging like somebody caught in a tree and that's when you can really see the cabling and it's the exact shape of a body, same size, everything, but it's just covered in moss," Collins told Australia's ABC Radio last week. "It's exactly what it looks like - just somebody caught in a harness, in a seat harness."