The trio of tourists rescued from Mt Taranaki on Sunday evening were caught in a flurry of snow ice and rock - just as they were about to be winched off the mountain.
The three were traversing a route called 'The Policeman' on the eastern side of the mountain, which runs from the ski field to the summit.
Police said at 4:40pm this evening someone raised the alarm, over concerns the tourists wouldn't make it down the Eastern Summit Track of Mount Taranaki before daylight ended.
While the rescue helicopter was preparing to take off, the trio were hit by the avalanche.
Police said rescuers needed to navigate falling rocks and lumps of ice that ranged in size from a little golf ball to a football before they could reach the three tourists.
One is thought to have a broken arm, while the others have minor injuries.
A helicopter and three alpine cliff rescue specialists formed the rescue team, which managed to successfully pluck the group off the mountain and to safety by 8pm on Sunday.
They were transported to Taranaki Base Hospital for medical treatment.
The man who remains in Taranaki Base Hospital is in a stable condition awaiting surgery, a hospital spokeswoman said.
Weather conditions in the area were clear at the time.
Police said the incident was a "timely reminder" for those heading outdoors to check the conditions for their planned routes prior to setting off and ensure they were well equipped with the appropriate clothing and gear.
It's not the first incident on Mt Taranaki this year.
In April, a climber was taken to hospital after being hit by falling rocks, an English tourist had to be airlifted out after she got lost and a 41-year-old woman was stretchered out when she injured her knee in a fall.
To assess the avalanche risk go to the New Zealand Avalanche Advisory website: http://www.avalanche.net.nz/
Further safety advice for outdoor activities could also be found at adventuresmart.org.nz.