Fears are growing for a man missing in a vast bush area near
Auckland since Saturday.
Ronnie Fong, formerly known as Ronnie Kumar, was lightly dressed when he went into the Hunua Ranges where temperatures have been below zero.
Rescuers know time is of the essence as they search for him.
The 36-year-old left for a day walk on Saturday morning wearing only shorts, a t-shirt and a light jacket.
Search and rescue co-ordinator Sergeant Dene Duthie says searchers are concentrating their efforts in an area between two tracks.
Texting his brother on Saturday afternoon, Fong said he was running late.
"I'm pretty worried now, yeah. I'm just worried," said Margaret Kumar, Fong's sister.
His family is well aware of the facts - Fong faced the coldest night of the year on Saturday and by now is likely to be suffering from hypothermia.
"It got down to about minus three degrees here, so it's very cold. Now it's a bit warmer but there's a lot more wind and heavy rainy is forecast," Duthie said.
Fong is a bio-engineer at Auckland's Middlemore Hospital, having moved to New Zealand from Fiji 18 years ago.
His family say he is physically and mentally fit.
"He's into martial arts. He hikes every weekend, usually Saturdays, Sundays, sometimes during the week he goes for runs," Kumar said.
Wind grounds helicopter
The wind picked up in the Hunua Ranges which means searchers can no longer use an Air Force Iroquois helicopter.
This has made the operation more difficult as the area they are searching is very remote and they are now forced to walk or drive into the bush.
Police say it is likely the missing man confused a Department of Conservation bait line for a walking track.
But with a search team of 70 on his trail, his family are not
giving up hope.
"I'm sure he'll be fine. But he'll probably panic a bit because it's quite cold out there and he hates the cold," Kumar said.
Panic, searchers say, is no use to Fong now as he needs to conserve energy in his battle against the elements.
Police want to hear from anyone who was in the Hunuas yesterday, especially in the Mangatawhiri and Waharau areas, even if they did not see the man.