One of New Zealand's most experienced mountaineers and his son are dead after an avalanche on K2, the world's second highest peak.
Marty Schmidt, 53, and his son Denali, 25, were attempting to conquer the summit in Pakistan.
New Zealand Alpine Club general manager Sam Newton said on Monday night the pair have not been in radio contact with Base Camp for a couple of days and their worst fears appear to have been confirmed.
"In recent hours tonight we've heard reports from people at Base Camp that they are sure that Denali and Marty have been killed by an avalanche."
He described Marty Schmidt as a highly regarded mountaineer who had climbed Mount Everest as a guide in May this year. Denali Schmidt was also an experienced climber.
Mr Newton said K2 is a particularly brutal mountain and hard to climb.
A blog post by climber Adrian Hayes, understood to be at Base Camp, said the Schmidts climbed from camp 2 to camp 3 last Friday while the rest of the party returned to Base Camp due to dangerous snow conditions.
Pakistan Alpine Club president Manzoor Hussain told Morning Report that two sherpas were sent to investigate after the pair lost contact with base camp on Friday.
On Sunday, the sherpas reached camp number three which had been hit by an avalanche.
There was no sign of the climbers, but they found climbing gear including crampons and ice axes.
Mr Hussain said it was likely the avalanche hit while they were sleeping. He said camp three is extremely difficult to navigate and does not allow for deviation to conduct a search and recover bodies.
Marty Schmidt worked as guide for the Tekapo-based Alpine Recreation company at times. Owner Anne Braun-Elwert said he was a very disciplined man and very driven.