Rescue teams scouring the Tararua Range for missing Wellington man Darren Myers will make a final four-day push through the freezing "very unkind environment", as one volunteer today broke his leg.
Wellington based UK man Darren Myers, 49, was last heard from on May 30 as he was tramping through the Northern Crossing of the mountain range north of the Wellington Region.
With Myers still lost nine days on, police search and rescue incident controller Tony Matheson said the situation is getting increasingly "grave", however police still hold out hope he is alive.
"We want an outcome but to be frank searches like this do not just continue for ever and ever, and we are slowly progressing towards what would be a suspension," Matheson said.
"We've got the family at the search base here every day, and they have an eyes-wide view of what's taking place here."
Matheson said there are 16 search volunteers broken up into four separate teams working up to 18 hour days, and there is "potentially" four more search days.
One volunteer was airlifted to Masterton Hospital today via helicopter after breaking his leg on a slippery creek bed.
"He rolled his ankle and fractured his tibia while searching a creek bed," Matheson said.
"He's now got his leg in a cast and is back home now. That's an example of the nature of the conditions.
"The guys are working in the middle of winter, off-track, in a slippery and very unkind environment."
A whole new 16 searchers will be rotated into the operation to begin tomorrow morning.
"Because of the isolation factors for the volunteers a lot of them struggle to commit longer than two or three days," Matheson said.
"We're looking for four-day commitments because it takes so long to get the people in there with flying conditions, and once they're in there you can't necessarily get them out again in a hurry.
"So the whole thing is difficult, it's isolated, it's hard to get in there. It's hard to get people out. When you do get them in there, the weather can very easily stop them from working, it's hazardous."
Fellow hikers in the Tararua Range have been asked to leave food, firewood, and any clothing at huts in case Myers has managed to travel beyond the search parameters determined by the police team.
"We determined in our search area what is high probability to us but that doesn't necessarily negate the fact that if Mr Myers remained energised and managed to travel through some pretty extreme country and get out of our search area, he still could pop up at one of those country huts," Matheson said.
The leader of the police search operation also urged recreational flyers to be conscious of helicopters in the airspace above the ranges.
Matheson also gave an insight into the unforgiving elements Myers would have endured in the Tararua Range.
"If he's been high up in the alpine level since Thursday, the situation is not good at all, and I guess you'll read into what I'm saying in that," Matheson said.
"If he has managed to get himself down low, get himself into a place of shelter and safety, then things could still potentially be good for him. But we've also had some extreme weather conditions."
The freezing temperatures and damp conditions were also a major problem, Matheson said.
"You could reasonably expect that his primary layer of clothing is at the very least damp, if not wet. But over the last 10 days he will have had to delve into any secondary layers of clothing he may have had.
"The extreme weather we've had so far is -14C in the alpine environment. So when you're looking at a man who has now been living there for 10 days wet and cold, every night will have been an obstacle for him, and during the day."
Myers' brother-in-law Duncan Styles said "every day is D-Day for us" yesterday on day seven of the search
"But as you get to the end of each day and there's no news then D-Day never comes."
The family were reluctant to start thinking about life without Myers, Styles said.
"It's the big unknown. What do you do? It's like a grieving thing that we are going through but we are staying positive that Darren will be found alive so we may as well carry on.
"We definitely just don't want to plan what life would be like if it doesn't work out."
Myers, an experienced tramper, set off on the hike last Tuesday. His last contact was a text message to his wife Kim Shaw last Thursday.