The search for a missing West Coast helicopter will resume tomorrow.
The Robinson R44, carrying a pilot only, was believed to belong to Helicopter Charter Karamea.
NZRCC spokesman Steve Rendle said tonight the Nelson Rescue Helicopter had used night vision equipment to search an area of the Kahurangi National Park, near the Nelson ranges.
The area, about 35km west of Motueka, had also been searched earlier today, he said.
The missing helicopter and another chopper left Karamea about 8am today to fly to Nelson for maintenance work on one of the aircraft.
The alarm was raised by the pilot of the second helicopter about midday when the missing helicopter failed to arrive at the destination.
"They weren't in sight of each other during the flight and as we understand it there was no radio communication between them," Mr Rendle said.
The search area is "steep, bush-covered terrain."
An emergency locator beacon from the helicopter had not been activated.