The parents of an English tramper missing in Paparoa National Park will arrive in New Zealand tomorrow to join the search for their son.
The man is understood to be 28-year-old Stephen Bennett who was reported missing at about 8.45pm on Saturday after he did not return from a morning walk up Mt Bovis, inland from Punakaiki. He set out at about 8am.
A police spokesman would not confirm it was Mr Bennett, but in a release police said his family was travelling to New Zealand.
Mr Bennett's sister, Amanda Adams, has been urging people to share a missing person's poster for her brother on Facebook.
In the poster he is described as having short mousy blond hair, blue eyes and ginger facial hair. He has a slim build and is 172cm.
On Facebook, Mrs Adams said her parents were flying from the UK and due to land in Christchurch tomorrow morning before being transferred to Hokitika.
Mr Bennett, who had been on a working holiday in New Zealand for three weeks, was lightly clad and only carrying a day pack when he went for a walk in the park, south of Greymouth on the west coast of the South Island.
Two helicopters and 15 ground searchers are involved in the search.
West Coast area commander Inspector Mel Aitken said: "Helicopters with heat-seeking devices and committed ground teams with a huge amount of expertise are involved in this search.
"Our thoughts are with the family at this time, as we continue our best efforts to reach a positive conclusion to this rescue."