Three aircraft were dispatched on Wednesday to rescue an Israeli couple stranded in the Mackinnonshelter on the Milford Track.
The pair activated an emergency locator beacon from inside a shelter (rather than out in the open), causing it to send a scrambled signal and hamper-ing rescuers' efforts to find the man and woman (both aged 30).
Wanaka Search and Rescue alpine cliff team leader Gary Dickson said a signal was originally picked up from within the remote Olivine Ice Plateau, a designated "wilderness area" within the Mt Aspiring National Park, about 3am.
A helicopter, flown by pilots Alex and Charlie Ewing, was dispatched from the Aspiring Helicopters base in the Matukituki Valley to try to locate the signal.
High winds and rain forced their aircraft back from the Olivine Ranges, so the Rescue Co-ordination Centre sent out a Nomad fixed-wing aircraft capable of flying to 12,000 feet.
A third helicopter was later sent from Cromwell about mid-morning after the beacon's apparent location shifted to the West Coast.
Mr Dickson was on the third helicopter and said flying conditions at the time were approaching borderline.
A signal location could not be pinpointed until about 11am, when it suddenly firmed from a spot near Milford, he said.
The pair were quickly found and then airlifted to Milford and taken back to Te Anau by bus.
They were drenched while tramping to the shelter and took refuge inside from an extreme wind, rain, and hailstorm.
The woman's partner became concerned after she began shivering uncontrollably in the middle of the night and, fearing hypothermia, had activated the beacon, Mr Dickson said.
The rescue was "a bit of a bizarre one", Mr Dickson said, and he stressed people had to activate locator beacons outside to ensure a clear signal.
