Tony Richards is not a faint-hearted man.

But as he staged a daring midnight rescue in remote Queensland, he was pretty glad he didn't know about the croc stalking the man he was about to save.

The chopper's pilot had spotted the hulking reptile but only after Mr Richards had unplugged his earpiece and winched himself into the darkness of the Lakefield National Park.

Below him was a lost camper who had resorted to eating tadpoles and bugs - and the croc, which had intended to make the camper its dinner.

Mr Richards is no stranger to outback rescues, so he assumed there might be crocs around and worked fast.

But he says he did go a bit weak at the knees when he later learned the croc had crept to within 10 metres of the camper.

"It does put you on edge," he told reporters on Monday.

The man had been missing for 36 hours, and had wandered for about 40km, when help finally arrived about midnight on Saturday.

The crew of the Emergency Management Queensland helicopter spotted him after he activated the flash on his camera.

Desperate to be seen, he'd walked into the only clearing in sight - on the edge of a croc-infested creek.

Pilot Darryl Humphreys said the camper had been extremely lucky.

"I looked down and there was a croc directly across from him, it had been stalking him and was about 10 metres away," he said.

"The guy told us afterwards that he'd heard a few things moving around him."

The camper, who was dirty and shaken but unhurt, told his rescuers he'd survived by eating green ants, tadpoles and grasshoppers.

He'd gone in search of help after he and his friends became lost on Friday.

His friends managed to walk out of the bush and raise the alarm on Saturday afternoon and a rescue mission was launched.

But the campers' ordeal might not be over yet.

Authorities are investigating why they were in the national park, west of Cooktown, which is closed to visitors.