A huge bush fire that has raged across Great Barrier Island in the Hauraki Gulf for more than a day is under control tonight.

Three helicopters with monsoon buckets and 40 rural firefighters have reduced the size of the area burning near Claris airfield and contained other sections of the fire, Auckland principal rural fire officer Bryan Cartelle said.

Diggers have excavated firebreaks and the helicopters and fire crews would continue to work until dusk on the remaining 8 hectares that are burning.

Two new Department of Conservation (DoC) firefighting teams and additional crews from Nelson and Rotorua arrive tonight and will relieve today's crews from tomorrow morning.


"I would like to thank all the crews and everyone who has gone the extra mile today - it's been a big effort,'' Mr Cartelle said.''

Northeasterly winds were expected to drop from 20-25km/h to less than 10km/h this evening, aiding the firefighters' efforts.

St John had received no reports of fire-related injuries from the island.

Extra police officers will be on the island overnight.

The cause is being investigated and initial reports of the fire being suspicious could not be confirmed, said a Northern Fire Communications spokesman. It is unknown if the emergency was caused by a 5000 square metre vegetation fire tackled on Sunday reigniting.

Meanwhile a suspicious scrub fire that burned 200ha of scrub near the Kaipara Harbour is also under control.

The fire started on DoC land at Kellys Bay on the Pouto Peninsula, southeast of Dargaville, yesterday morning.

Four helicopters and 80 ground crew battled to bring the fire under control.