Waverley Fire Station Chief Alan Hickford said fire services from Hawera and Taranaki also attended the blaze.
"Hawera responded initially with the Hawera water tanker. But because of where it was we couldn't get vehicle access to it. Taranaki rural fire crews came in and helped us out."
Mr Dunbar said the fire was fully extinguished at 4.30pm.
Police were called to assist during the incident. Detective Craig Jackson said they arrived at the scene mid-afternoon.
Mr Jackson said there would be an investigation into the incident.
"Obviously it's a bit hard out here, with no neighbours for miles," he said.
Security guards would be keeping watch over the area.