An Australian climber rescued on Saturday morning from Aoraki Mt Cook sheltered in an ice-cave for two nights.
Miles Vinar, 42, of Perth, saw his brother Dr Mark Vinar, 43, fall off Zurbriggens Ridge on Thursday.
Dr Vinar is presumed dead. A search for him was called off on Saturday morning because of the risk of an avalanche.
Miles Vinar attempted to get back to the safety of Plateau Hut. But the weather worsened and he decided to dig a small ice cave, as his brother carried their tent in the fall.
The Department of Conservation says the decision probably saved his life.
Spokesperson Shirley Slater says the brothers were moderately experienced, having climbed in New Zealand and overseas before.
The ABC reports 18 Australians have been killed climbing Aoraki Mt Cook, which is New Zealand's highest mountain.
A Japanese climber was rescued on the mountain on 5 December after being trapped for a week by bad weather. His guide died of exposure.