
Mr Collins was leading an expedition of 19 assorted off-duty police officers, businessmen and photographers along the Trail - thought to be some of the most rugged hiking terrain in the world.
The discovery was made on 28 August, by one of the members of the expedition - a man who has requested to be referred to only as John.
He had stopped to take a photo of flowers in the canopy, Mr Collins told the BBC.
"If you knew the trek, you don't often look up, because you're watching your footfall the whole time - it's very slippery and muddy, and can be quite dangerous," Mr Collins said.
"John stopped to take a photo of the canopy, and saw something that didn't seem quite right through his viewfinder. He watched it for a little bit longer and the wind blew, and caught it, sending it spinning, and it seemed to be a body."
There was an immediate sense that an exciting discovery had been made, Mr Collins said, and other members of the expedition team were called back to take a look for themselves.
That it was a body was not immediately apparent, Mr Collins said.
"I'll be honest, I couldn't even see it at first, because it was quite high up in the canopy, about 12-15 metres [40-50 feet] up," he said.
But once again the wind blew, and it started spinning and dangling. That was when you could make out the shape of a body. But it was covered in moss, and if it had been me, I would never have discovered it, even looking straight at it, but when it started swinging back and forth, you could see the shape of it.
"And when it swung backwards it had around it what looked like a sort of aluminium frame or harness, and it appeared to be caught in a cable in the tree."
The assumption at this point, said Mr Collins, is that the body - if it is a body - is that of an airman who was wearing some kind of parachute harness at the time of his death.
One expedition member even thought he could make out a moss-covered pair of flying goggles around the corpse's neck.