Bad weather in the Kahurangi National Park has dashed hopes of carrying out an aerial search for a man missing for almost a week.
Alistair Levy, 54, from Palmerston North has not been heard from since last Sunday when he sent a text message from the summit of Mount Owen, west of Nelson.
Ground searches were carried out on Friday, but poor weather prevented the police from completing an aerial search.
On Saturday, wet weather again hampered the efforts of searchers looking for Mr Levy.
Five teams of searchers, including dogs and specialist cavers, have spent four days searching, with little success.
Nelson Marlborough Rescue Helicopter pilot Jarrod Colbourne said he was supposed to comb a final area on Saturday that hadn't already been covered.
He said ground searchers found evidence a tramper may have been in that particular area.
Police said they hold grave concerns for Mr Levy's welfare considering the time he's been missing and the challenging terrain.