Rescuers who went to the aid of six trampers in Mt Aspiring National Park on Tuesday ended up finding five more missing people.
A six-member tramping party activated a personal locator beacon about 7pm on Monday but bad weather meant a helicopter search could not begin until first light on Tuesday.
Rescue Coordination Centre mission controller Keith Allen says the rescue helicopter was forced to land due to the bad weather, and as it was doing so, two hunters who were overdue to return from their trip flashed a torch to attract the pilot's attention.
When the helicopter later flew on to find the six trampers, they discovered three others as well.
One of those rescued was Auckland woman Kathryn Firth, 36, who said only light rain was falling when the tramping party of six set out on the Rees-Dart Track.
Conditions quickly changed the group could not make it to the Rees-Dart Hut due to swollen rivers. They were forced to huddle in sleeping bags, in the shelter of a rock.
She says it was a long night, and they were very cold, but were well equipped for a night in the open. Ms Firth says next time she would consider doing the walk during the summer months instead.
Another of the rescued trampers, Craig Howie, has told of how his party helped a group of three people in their 60s who were also caught off guard by the bad weather.
Mr Howie says the three were well-prepared and fit but getting cold, and one told him he wasn't confident they would have made it back without help.
Keith Allen says worsening weather conditions, including sleet, are forecast for the area on Tuesday.
MetService has also issued a road snowfall warning for Milford Road, predicting up to 2cm of snow between 6pm and 10pm.