Emergency services were alerted to the fire off State Highway 30, near Lake Rotoiti, about 10.51am today.
A Rotorua Daily Post staff member at the scene said fire crews now had the blaze, which came within 50m of nearby houses, under control.
He said the fire was about 100m from the road and had been at least 50 square metres wide, if not bigger.
Earlier a northern fire communications spokesman described the fire as "a very large fire, reportedly about the size of a rugby field."
A police northern communications spokeswoman said at least one lane of the highway had been blocked due to the fire.
Traffic was now flowing in one lane.
Fire crews are investigating the cause of the fire.