A helicopter was expected to fly to Brewster Hut in the Haast Pass area today to check on a tourist who had not returned from a walk yesterday.
A Department of Conservation worker raised the alarm after finding the woman's rental van at a car park near the summit.
West Coast police search and rescue co-ordinator constable Mike Tinnelly said they were waiting before mounting a full scale search.
"We are waiting to find out whether the woman spent the night at the Brewster Hut." The walk to the hut was about three hours.
"If she left later yesterday, she may have stayed the night and be coming out today."
- The Greymouth Star