Key Points:

The country's largest ski resort is refusing to comment on the safety of its trails after a 29-year-old Wellington woman died while snowboarding at Mt Ruapehu yesterday.

Police said the woman fell 15m into a "waterfall hole" on Turoa's western slopes about 1.20pm, suffering "significant" head injuries.

The name of the woman, who was boarding with two girlfriends on an advanced trail known as the Organ Pipes at the edge of the skifield, had not been released last night.

Sergeant Graeme Rumble, of Ohakune police, said she "got into difficulties" when close to the lip of the drop-off.

"She was uncomfortable with continuing on her intended course due to a hole in the snow caused by an underground stream."

There was a sign warning skiers "not to go that way", he said.

The woman was trying to climb back up the way she had come when she slipped and "got into a slide".

Ruapehu Alpine Lifts general manager Dave Mazey confirmed the incident happened within the skifield boundaries but refused to comment further, saying it was "a police matter".

Skifield staff were also silent about the death, referring the Herald on Sunday to a marketing manager who did not return calls.

The woman's "devastated" companions were last night yet to be interviewed. Police said her partner had also been on the weekend ski excursion but was not with her when she fell.

The Herald on Sunday understands at least one fellow skier risked their own life, clambering into the hole after the woman.

Malcolm Pullman, who was skiing at Turoa yesterday, had spoken to a medical student who had come across the scene. "She was still in the hole. He raced off to get help."

A doctor who was skiing with the student is understood to have made the risky trip into the hole to try to resuscitate the woman but found her unresponsive, with severe head injuries.

Pullman, who later visited the site with the student, said they were surprised it was "not fenced off or anything".

He said the hole was up to 2m wide and looked "dodgy" and he was surprised to see other boarders and skiers jumping it before the skifield closed.

Police said the death had been referred to the Wellington coroner.

While investigations were continuing, it appeared the dead woman had "done everything correctly" in attempting to avoid the drop-off, describing her fall as a "tragic accident".

A crew member of the Lowe Rescue Helicopter, sent from Hastings to retrieve the woman's body, said it was a clear day and there did not appear to have been any visibility issues that could have contributed to the accident.

Tauwira Ski Club president Paul May said yesterday from Wellington that while he had not heard about the accident, it was common for areas above waterfalls, that were generally well-covered during the winter, to become hazards as snow melted in spring. "The snow may not have the stability any more to take the weight of a skier."

A photographer based at Whakapapa said advanced skiers knew to stay "well clear" of such areas but there was a growing trend for people to jump them.

A motorcyclist was killed in a crash west of Taumarunui yesterday afternoon. Police said the man, aged about 40, was riding with the Ulysses Motorcycle Club when he lost control and hit a fence on Ohura Rd, Tokirima.

A 32-year-old man is missing on the West Coast after the Canadian canoe carrying him and four others capsized on the Grey River near Greymouth yesterday afternoon.

One adult and three children made it to shore but Constable Sean Judd said last night that fears for the missing man's safety were growing.

All the children were wearing lifejackets at the time of the accident, but it is believed the missing man had not put one on.