Wellington  - An Australian climber, missing after falling down a crevasse on Mount Cook in New Zealand's Southern Alps, is presumed dead after his brother was rescued on Saturday, news reports said.

Miles Vinar, 42, of Perth, told police his brother Mark, 43, disappeared as they were climbing down a ridge after abandoning a bid to climb the 3,754-metre mountain, New Zealand's highest peak, in worsening weather on Wednesday night.

Miles said he thought his brother had fallen at least 500 metres and he knew Mark would not have survived, Radio New Zealand reported.

Miles, who survived by digging himself an ice cave, was picked off the mountain unhurt by a rescue helicopter at dawn. A search for his brother was abandoned because of the avalanche risk on the mountain.

This would be the second death on the mountain in a week. A Japanese mountain guide died of exposure on Mount Cook on December 5 while his companion was rescued. (dpa)