A family were still sleeping inside their home when it was set on fire during the weekend, one of a series of arsons under investigation at Lake Taupō.
Five properties were damaged in the fires in the early hours on Sunday, police say, and two were completely destroyed.
They were all on the eastern side of Lake Taupō in Tauranga Taupō, Waitetoko and Hatepe.
Police say the Hatepe fire is "particularly concerning" as a family were asleep inside the house when it was set alight.
They managed to escape with any injuries, police say.
“We would like to assure the public police are committed to fully investigating this matter and holding those responsible to account," Detective Sergeant Andy Livingstone says.
Anyone who saw vehicles travelling on or around State Highway 1 in the early hours of Sunday, especially in the three settlements that were targeted, is asked to contact police.
“We would especially be keen to hear from anyone with dashcam footage that may have captured vehicle details," Mr Livingstone says.
Anyone with information about the arsons or people involved is also asked to contact police.
People with information can contact Taupō police on 105 and quoting case number 200114/9694, or anonymously via Crimestoppers on 0800 555 111.