Bad weather threatens to hamper the search for a tramper missing in Central Otago, which is in its fourth day.
David Charles Palmer, 53, from Dunedin, left for a three to four hour tramp in the Ahuriri Valley on Saturday.
A search for Mr Palmer has been underway since Sunday evening.
Police said six search teams of about 50-60 Search and Rescue volunteers from Central Otago, the Catlins, Twizel, Tekapo, Fairlie and Wanaka, accompanied by three SAR dogs, are scouring the area he is believed to be in.
"Based on information gathered from family and friends the search is now focused more specifically on the Dingleburn Track area, based on a sighting of Mr Palmer in that locality on Saturday morning.
"However Police and SAR advisors are continuing to keep an open mind to ensure that all possibilities are covered," Sergeant Tony Woodbridge said.
An Air Force Iroquois arrived yesterday evening with a team of seven army staff, and will drop ground search teams into the area.
However weather threatens to limit the search today, with cloud coming down and steady rain in the area.
Police said the air temperature in the area was relatively warm overnight.
A Fire Service command truck from Dunedin has been brought to help with communication, which has been difficult due the remote and isolated location.
Police remain hopeful Mr Palmer, described as an experienced tramper, will be found safe and well, however concerns for his safety are mounting.