Robin Severinsen, of Te Kuiti, said he and a hunting companion discovered the body, which was flown out of the bush this week, at the start of a 12-day hunting trip in a back-country wapiti deer block, on March 24.
They had been walking up McDonald Creek from Bligh Sound, 40km south of Milford Sound, for about seven hours when they came across the body of a man inside a sleeping bag, Mr Severinsen said.
They were taken aback when they came across the body.
"We weren't looking for that sort of thing when we went in there."
But with no way of notifying authorities, they could only carry on to where they had arranged to meet two other hunters.
The hunting party had won the right to shoot through a ballot.
Due to the remoteness of the area, they had to wait until a helicopter came to pick them up to take them to Te Anau on Monday before they could inform police.
Mr Severinsen (68), an experienced hunter, said the body was "quite badly" decomposed, but he thought the man might have been middle-aged and possibly part-Maori.
Asked how he reacted to finding the body, Mr Severinsen said: "I'm a farmer; I've seen a few things."
The discovery had led to some sleepless nights, though.
"Oh, we lay there at night thinking about it."
"It was not clear what the man had been doing in the area.
"A pack was nearby, but no tent or other equipment, and no guns.
"I'd definitely say he was underprepared.
"It's pretty remote in there."
The pair had been "lucky" to find the body, as they only followed the creek because it was the same one they followed while hunting in the area last year.
Mr Severinsen went back with police on Tuesday to show them where the body was.
The incident had not put him off the area.
"It's just one of those things.
"I love Fiordland. I'll be back."
