It also threatened the Rotorua Archery and Kiaora Club buildings, near the Rotorua waste treatment plant.
Firefighters believe the fire was also arson, and linked to about 10 fires in the area over the past four to five months.
Rotorua Fire Service senior station officer Colin Rolfe said firefighters were called out to an area behind the waste treatment plant about 4.30pm on Tuesday. Mr Rolfe said the area had been hit at least 10 times in the past five months.
"There have been so many fires down there in the last four or five months," Mr Rolfe said.
If firefighters and fire appliances were tied up dealing with "needless" arson, people's lives could be put in danger and homes could be be destroyed.
"It limits the amount of people we've got to go to that," Mr Rolfe said. "You could say that it puts lives at risk in Rotorua for needless acts."
Mr Rolfe said there were thermal pools near the waste treatment plant, making firefighting tricky.
"You've got to be careful where you're putting your foot."
Sunday's fire started about midday and took firefighters about two hours to bring under control.
At times the blaze was clearly visible above the trees which towered the scrub bordering the walkway connecting Ngapuna with the city centre.
Hundreds of holidaymakers and locals watched the fire as it raged out of control with thick black smoke billowing above the trees.
Meanwhile, the Taupo Fire Service has also been dealing with a suspected arsonist.
Firefighters were called to a suspicious forest fire at Lake Ohakuri in Taupo about 8pm on Tuesday.
Station manager Graeme Trainor said firefighters were at the fire until about 11pm when the Pumicelands Rural Fire Authority took over.
He said the fire started on the Ohakuri Rd roadside bottom but they were unable to put it out as it had reached the forest.
"We couldn't even get hold of it," Mr Trainor said.
* Can you help?
Call police on 0800 TIP OFF if you know who is responsible for these fires.
- NZPA
