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.