A search team is being assembled to look for a hiker who rang police after becoming lost in Arthur's Pass National Park.
The hiker, who is alone on or near the Mt Aitken Track, phoned police at 12.15pm, a spokesperson said.
Police did not have the person's age or sex. A search and rescue team was assisting.
The Mt Aitken Track is described by the Department of Conservation as an advanced tramping track.
The weather in the area is partly cloudy and 17C.