A hiker with medical training says if he and his companion had not come across 16 ill-prepared trampers attempting the Tongariro Alpine Crossing in freezing conditions some may have died.
A tour operator has been criticised by the police for dropping off the group which got into difficulty on Saturday and needed to be rescued from the 19km track.
Ghaz Jabur and tramping companion Graham Plows were properly equipped when they hiked up to near the summit and came across one of the group who was coming down for help.
Mr Jabur walked to the rest of the group and helped them down to shelter.
He said many were suffering hypothermia and one woman was very close to death.
Police say the group were inexperienced, lightly-clad and the early stages of hypothermia were setting in when the two trampers came across them and raised the alarm.