A police-led search around Lake Wanaka for a missing helicopter and pilot has been suspended for the day and will resume tomorrow at first light.
The helicopter was reported overdue about lunchtime yesterday.
And oil slick and debris form the Robinson helicopter was later spotted by searchers at Stevenson's Arm on Lake Wanaka.
The Police National Dive Squad began a search of the lake this afternoon.
Police today confirmed the pilot of the helicopter is 39-year-old Matthew Timothy Wallis and said he is not believed to have survived the crash.
Mr Wallis, the son of Warbirds over Wanaka founder Sir Tim Wallis, was the only person onboard the Alpine Helicopters helicopter.
Detective Sergeant Derek Shaw says police are liaising with the family and keeping them updated on the progress of the search.
Many local people have been involved in the operation, including LandSAR and Coastguard volunteers, Mr Shaw said this afternoon.
"We would like to thank the community for their offers of support particularly those with boats and aircraft," he said.
"We know Matthew is well-known in the area and many people are concerned for him."
Alpine Helicopters says at 12.54pm on Saturday, a helicopter left its base with one person onboard on a private flight from Wanaka Airport to Mount Aspiring National Park.
The flight was expected to take approximately 15 minutes. At 1.08pm the helicopter was unable to be reached by radio. Its last satellite position report was 1.03pm.
At 1.16pm the aircraft was deemed overdue and at 1.19pm two aircraft were sent to search for the missing helicopter and pilot.