Dog reunited with owner after falling down NZ waterfall

When a hiker fell from a 55-metre waterfall in wild New Zealand bush, rescuers were forced to evacuate the badly hurt woman without her dog, which couldn't be found.

After strangers raised thousands of dollars for a search, border collie Molly was flown to safety by a helicopter pilot who was determined to reunite pet and owner.

A week earlier, an emergency rescue helicopter found Jessica Johnston with cuts and bruises after a fall at a rocky spot at the waterfall on the South Island.

She was airlifted on March 24 but they were forced to leave without her pet.

Molly was bedraggled and hungry when she was found on Tuesday, just a few metres from the spot where the hiker had been lucky to survive.

"I contacted her in hospital and said I'd go for a look for it," said Matt Newton, the owner-operator of Precision Helicopters New Zealand, which is based at Hokitika Gorge near the Arahura River where Molly went missing.

"I went and looked for the dog several times and no avail."

Unwilling to give up, Newton and his family launched a fundraiser to pay for more flying hours and advanced search gear.

Offers of help and donations poured in, with strangers pledging more than $NZ11,000 ($A9000) for a search.

It was enough to fund three more hours in a helicopter using thermal-imaging equipment.

On Tuesday, Newton took to the skies with a veterinary nurse, volunteer searchers and a dog named Bingo in a renewed search for Molly.

"We struck jackpot within about an hour," he said.

There had been no sign of Molly at the waterfall when Newton previously searched the spot, he said.

It wasn't clear if the dog had also fallen from the waterfall or if she had eventually made her way to the spot where her injured owner landed.

The helicopter dropped low enough for a volunteer to disembark with the rescue dog Bingo to help coax Molly to safety and keep her calm.

Newton thought the dog had survived by eating feral animals during her week in the wilderness.

The dog was in "surprisingly good condition", the pilot said.

He sent word back to the helicopter base, where other volunteers waited to take turns in the search.

"Instead we just had a big barbecue and all had a cuddle with Molly."

Hours after the dog's rescue, Johnston, still battered from her fall, arrived for a tearful reunion.

"I think that'll speed up her healing process somewhat," Newton said.

"Having your dog back, that's for sure."