A fire in Waipoua Forest has burned through 30ha of scrub as a team of 30 firefighters continues to ensure the blaze has been contained.
A team were on the ground last night ensuring hotspots did not ignite again.
A surfer on the west coast near Kawerua, 14km south-east from the entrance to the Hokianga Harbour, raised the alarm after seeing smoke coming from scrub about 4.15pm on Thursday.
Two helicopters worked until dark that day dumping monsoon bucket loads of water on the fire. Yesterday, a team of 30 was working on hotspots and flare-ups. They were expected to work through the weekend using thermal cameras to detect hotspots.
Department of Conservation Kauri Coast community relations manager Karen Joyce-Paki said it was unclear at this stage how the fire had started but it had been traced to a pampas bush in an area of logging slash, where pines had been cleared and scrub had started to grow back.
Ms Joyce-Paki said investigations into how the blaze was sparked had started yesterday.
"A popular walking track passes along the coast there and campers were in the area. It was actually a surfer who spotted the fire and raised the alarm."
She said the kauri tree Tane Mahuta, Waipoua's most famous resident, was not in any threat from the blaze.
The winds were not strong and it was hoped the fire would be extinguished today.
Two helicopters were still on standby yesterday.
Meanwhile, Ms Joyce-Paki said, a fire that started in Kelly's Bay, about 50km southwest of Dargaville on Pouto Peninsula, on January 22 continued to burn as it had become deep seated in peat.
There were still a dozen firefighters on site working on hot spots.
Dargaville police are still investigating the cause of the Pouto fire that burned about 200ha of forest and is costing tens of thousands of dollars to fight, including $86,000 on helicopters alone.
Three helicopters and 80 ground crew battled for two days to control the fire in 50ha of pine trees and another 150ha of native scrub and wetland in the Punahaere Creek reserve, managed by the Department of Conservation.