The police and Fire Service are continuing investigations into the cause of a large fire near Kaimarama, on the Coromandel Peninsula.

The fire is believed to have started sometime on January 17.

'A large area of bush was destroyed as a result of the fire, as well as a number of dwellings in the area,” says a statement from police.

'The exact cause of the fire is unknown at this stage, however Police are speaking to witnesses and a full scene examination is being conducted alongside the Fire Service.”

If you have any information on the fire that could be helpful to the investigation, please contact Whitianga Police on 07 866 4000.

Meanwhile, firefighters remain at the scene with the New Zealand Defence Force's five-member firefighting crew working overnight Thursday to extinguish hotspots to prevent the massive bush fire south of Whitianga from spreading further.

'We got straight to work as soon as we arrived about 10 o'clock last night and finished about 6.30 this morning,” says Corporal Alex Walker, who is leading the NZDF's firefighting crew.

The firefighters – four from the New Zealand Army and one from the Royal New Zealand Air Force – have extensive training and experience in fighting bush fires.

After patrolling the fire perimeter, Alex says the team worked on hotspots, using shovels and axes to dig out embers.

'Hotspots can potentially flare up again, so we tried to extinguish them to help contain the fire.

'The ground was hot and there was smoke everywhere. We were walking through a light fog of smoke, using torches to light our way.”

The firefighters had to haul all their equipment over two kilometres of steep terrain, says Alex.

'We were conscious of our safety, so we stayed mainly on the tracks and kept away from areas where there is still live vegetation.

'Everyone was tired after working overnight but morale remains high and the lads are keen to get out there again today to help out.”

Major General Tim Gall, the Commander Joint Forces New Zealand, says the firefighters would be helping the National Rural Fire Authority over the next five days.

'Our firefighters have the experience and the skills to do this job.

'We are aware that this work involves immense physical labour and some risks, but we in the Defence Force are always ready to help the local community.”