A search for a Taupo man missing since Friday is now being concentrated on an island in Lake Taupo.
Leighton Kerry Grant left the central North Island town on Friday evening, but failed to return on Saturday night as planned.
The 35-year-old's car was found at Hallets Bay on Monday.
Police say searchers have discovered items belonging to Mr Grant, including a wetsuit, on Motutaiko Island.
They want to hear from anyone who has been in the vicinity of the island in recent days, who may have seen someone swimming to the island, or from any boaties who have taken someone there.
Police say they are concerned about Mr Grant's state of mind and warn that his reaction on being approached may be unpredictable.