Eleven houses were evacuated yesterday afternoon as the fire spread in pine forestry on steep terrain - but there was no reported damage to property, aside from the forest itself.
The blaze was contained but work continues to extinguish it fully.
Last night the Urban Search and Rescue unit of Emergency New Zealand (Fenz) deployed drones to identify hotspots.
“The drone technology can pierce the forest canopy and identify hotspots more efficiently,” said Fenz incident controller Steve Trigg.
“Not only did this find hotspots in the main Lee Valley fire, but also helped identify small hotspots in the adjacent two initial fires that were thought to be extinguished.”
Trigg said one helicopter with a monsoon bucket and 20 ground crew would continue work today focusing on extinguishing these hotspots individually - as well as extending the control perimeter.
“Those evacuated from their homes have been allowed to return, the road remains closed with the exception of monitored access to residents, the area is still an active fire ground,” said Trigg.
”We urge the public to stay away from this area so as not to hinder fire ground operations that are still active today.
”This is also to ensure both the public and our crews are safe as we continue our operations.”
Trigg said the investigation is ongoing but suspicious causes have been eliminated.
“With more sunshine and warm weather ahead for the next week, it’s again an important reminder to be vigilant around activities that can generate sparks during this very dry fire season, and that a simple spark can have devastating impacts on people, property and the environment, as well as pets and livestock.”