UPDATED 4.50pm

About 80 skiers have been rescued from a chair lift at Ohau ski area in the foothills of the Southern Alps.

The lift stopped about 2.15 this afternoon, when a skier dismounted awkwardly from a chair - causing it to swing and damage the bull-wheel, connecting with the cable.

At 2.30pm the decision was made to evacuate the 80 people on the double-chair lift.

The ski area's general manager Mike Neilson said staff worked their way from chair-to-chair, lowering the skiers down using a belay system, with a rope.

There have been no reports of injuries.

A police spokeswoman confirmed police were called to the Ohau Snow Fields at 2.40pm in response to reports of a broken chairlift.

Police gathered at Omarama Police Station to co-ordinate a response to it.

General manager and owner/operator of Ohau Snow Fields, Mike Neilson, said the chairlift stopped about 2.15pm after "someone dismounted in an unhappy fashion".

"I suspect something got caught so the chairlift has got caught up with the bull wheel and it has damaged it slightly."

He said the chairlift was "fairly full" when it stopped and staff are now going through the process of evacuating everyone from their seats.

"To make sure nobody gets cold we are going through the process of evacuating everybody.

"The lift stopped at about 2.15pm so it has just gone an hour now and it is normally about two hours to evacuate so they will be all off before too long."

He said police were called in to assist the evacuation as a precautionary measure.

"It is precautionary to get the search and rescue people in because many of them have experience in evacuating people from high cables.

"We have evacuation training with them, and they are on their way to give us back up but they may well find they get here and we have done it all, but we have taken the precaution of getting their assistance."

He said the evacuation process entails a belay process of pulleys and hooks.

"A pulley and hook goes over the cable and they run it down from chair to chair and belay them down.

"If the weather was bad then it becomes a bigger issue but it is very pleasant conditions so it is just a process we have to go through to get them all off."

He said the snowfields had two other lifts which were still working.

"We have had a very happy crowd up there, on a beautiful Friday afternoon. The conditions are really nice, sunny and warm and good snow conditions as well."

He said the chairlift would require heat and hammers to pop the bull wheel back in place.

The Ohau Snow Fields is a small family-run business near Lake Ohau in the Mackenzie High Country in the South Island.