DoC volunteer missing on Raoul Island

Raoul Island, in the Kermadec Islands, where a DoC worker has gone missing. Photo / supplied

A search is underway for a Department of Conservation volunteer who went missing on Raoul Island in the remote Kermadecs this morning.

The volunteer's vehicle and gear were found close to where he was carrying out water temperature readings at 6am today.

The remaining three staff and three volunteers on the remote island, some 1000km northeast of New Zealand, have been searching the shore but have found no sign of the man.

The Rescue Coordination Centre New Zealand (RCCNZ), which is coordinating the search, has sent a fixed-wing plane carry out an aerial search.

The aircraft was expected to reach the area about 7.20pm and would return to base at nightfall, after which a further response would be assessed.

RCCNZ has sent out a mayday relay broadcast to all vessels in the area in case assistance is required.

The Department of Conservation said it was monitoring the situation, with the safety and wellbeing of the remaining staff and volunteers its top priority.

The Kermadec Islands, which are managed by the department, is a chain some 250km long.

The largest island, Raoul Island, is the northernmost inhabited part of New Zealand. It is home to conservationists and volunteers.