The incident was escalated to a second alarm response as firefighters battled the blaze and carried out a search and rescue operation for the missing person.
Crews will likely remain at the scene for the rest of the night, the spokesperson said.
Assistant Area Commander Katie Pocock told the Herald at the scene that Fire and Emergency New Zealand was alerted to a house fire on Forest Hill Road in Henderson at approximately 8:37pm tonight.
On arrival, crews were confronted with a well-involved property fire and were advised that a person was reportedly inside.
The incident has been escalated to a second alarm, with eight fire trucks currently in attendance.
Firefighters are continuing operations at the scene, with more information to be provided as it becomes available.