A border collie missing for nearly a week in remote New Zealand bush has been found alive and reunited with her owner, after a volunteer helicopter search backed thousands of dollars raised by public donations.

Molly disappeared on 24 March when her owner, Jessica Johnston, fell about 55 metres down a waterfall while hiking in the Arahura Valley on the South Island’s West Coast.

Johnston survived with injuries and was airlifted out, but rescuers were forced to leave without the dog, which could not be found at the time.

For days, there was no sign of Molly in the dense, rugged terrain, and the chances of survival were unclear.

Matt Newton, owner-operator of Precision Helicopters New Zealand, said he decided to keep looking after speaking to Johnston in hospital.

‘I contacted her in hospital and said I’d go for a look for it,’ he said. ‘I went and looked for the dog several times and no avail,’ Newton said, as reported by Associated Press.

With costs mounting, Newton and his family set up a fundraiser to continue the search.

Donations from across the country raised more than 11,000 New Zealand dollars, allowing them to keep flying and use thermal imaging equipment.

The appeal drew support from strangers across New Zealand and helped bring in experienced volunteers, according to The Guardian.

On Tuesday, Newton flew out again with a small team, including a veterinary nurse and a volunteer who brought along a Jack Russell named Bingo to help calm Molly during the rescue.

‘We struck jackpot within about an hour,’ he said. ‘As we made our way up the river, we could see the dog in the thermal and then we could visually see it.’

Molly was found just metres from where Johnston had landed after her fall. It is not clear whether she had also fallen or had made her way back there over time.

The Independent reported that she was in a narrow, slippery area beneath the waterfall, surrounded by rocks and constant spray.

The helicopter dropped low enough for a crew member to get out and retrieve her, using food and Bingo to coax her in.

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

‘She knew what we were up to, I think,’ he said. ‘She behaved real well. She didn’t run away and she was pleased to be rescued.’

Despite everything, Molly was in a ‘surprisingly good condition’, the pilot said, adding, ‘Instead we just had a big barbecue and all had a cuddle with Molly.’

Hours later, Johnston, still recovering from her injuries, was reunited with her dog.

‘I think that’ll speed up her healing process somewhat,’ Newton said. ‘Having your dog back, that’s for sure.’

Johnston suffered a split elbow and extensive bruising in the fall.