A rescue operation is underway for a tramper missing on the Milford Track since Monday.
Police say the man, who had been intending to climb Devil's Armchair, was reported overdue shortly after midnight on Monday morning, and a search was initiated.
Before first light today, an aerial search using thermal and night vision technology was conducted.
A LandSAR dog will continue to search today in the area along the northern part of the Milford Track, a spokesperson said.