A close friend of New Zealand Prime Minister Helen Clark has died while on a alpine trip with her in the South Island, despite Clark's effort to revive him.
Police have confirmed the dead man was Gottlieb Otto Braun-Elwert, 59, a mountain guide who had taken Clark and her husband Peter Davis on several skiing and mountaineering trips in the past.
Braun-Elwert had what is believed to be a heart attack, Inspector Dave Gaskin, area commander for Mid-South Canterbury police, said.
Clark is understood to have been involved in lengthy resuscitation efforts on him after his collapse on Thursday afternoon.
St John's Ambulance said it received an emergency call from Mt Gerald in the Two Thumbs range in the Tekapo district, at 3.53pm.
It dispatched the Westpac rescue helicopter from Christchurch, with a St John advanced paramedic on board, to Tekapo, but neither it nor another local helicopter operator could reach the site because of what Gaskin described as "atrocious weather conditions".
Clark and Davis were reported to be safe in a hut on the mountain in the Two Thumbs range. Braun-Elwert is believed to own the hut on Mt Gerald Station.
Search and Rescue volunteers and a police search and rescue squad, including a St John advanced paramedic, were understood to have reached the hut and were preparing to evacuate the party, Mr Gaskin said.
"Due to atrocious weather conditions a helicopter which was dispatched from Christchurch has been unable to reach the location," Gaskin said.
Clark's spokesman said there was no danger to Clark or other members of the party.
Braun-Elwert had an alpine recreation business based at Lake Tekapo.
He had spoken of Clark and Davis as his most regular clients.
He had guided them more than a dozen times, on either cross-country skiing or climbing expeditions in New Zealand, South America and other countries.
In 2004, he took Clark and Davis on a four day ski touring trip.
Clark had to abandon a summit bid on Aconcagua in the Andes, with Braun-Elwert in 2001, because of bad weather and illness in a fellow climbing party.
They had crossed New Zealand's highest guided pass, the 2,105 metre Ball Pass on the Mount Cook Range, together the previous year, and later climbed Mount Kilimanjaro, Africa's highest peak.
Braun-Elwert was a member of the New Zealand Alpine Club and served on a ministerial reference group looking into issues of public access to NZ waterways and rural backcountry.
He held a degree in nuclear physics and immigrated to New Zealand in 1978.