Detective Senior Sergeant Mike Hayward, of Counties Manukau West CIB, said police and firefighters attended the incident, and an investigation had since begun.
“Police are working to establish what has occurred and will remain on scene.”
In an update this afternoon, he said a scene examination was carried out today alongside a fire investigator.
“We are continuing to work through our formal identification procedures, with a post-mortem examination also set to take place tomorrow.
“Given these inquiries remain in the early stages, we are continuing to treat the circumstances as unexplained.”
Fire and Emergency assistant commander Chris Delfos said the shed appeared to be a sleepout.
“Crews arrived and were faced with a well-involved, medium-sized shed,” he said outside the burned Tamaki Ave property.
“We did not have any indication that there were persons trapped in the building, and while the crews were extinguishing the fire, they unfortunately found the deceased.”
He urged people to check their smoke alarms and make sure they had an escape plan “so these sort of things don’t happen”.
Police and Fire and Emergency NZ have launched an investigation into the fatal fire. Photo / Anna Heath
Next-door neighbour Ravin, 48, said he saw flames burning about 4m high at the back of the house.
“I looked out of the window and saw flames really shooting up.”
He said the homeowner had lost her husband late last year. Another woman acting as her helper lived in the sleepout.
“I knew the lady personally, the owner. And the husband as well. I only saw the owner a few times, the lady.
“I came to find out that there was another lady living in the sleepout. She was like an assistant or helper to the owners.
“Seems like it was the assistant that was in the sleepout because she was the one who was around in the weekend.”
Ravin said it was “devastating” that someone had lost their life in the incident.
Ravin, 48, said a woman stayed in the sleepout. Photo / Anna Heath.
Another neighbour, Milika Pikula, 67, said she knew the owner well, but wasn’t aware that another woman was living in the sleepout.
Pikula said she went to church at 7pm and returned home to police and two fire trucks in the area.
“I haven’t seen fire or smoke ... the police said they found a body.”
Milika Pikula returned from church to find emergency services at the scene. Photo / Anna Heath
Fire and Emergency northern shift manager Garreth Lewis said multiple calls were received just before 9pm about the fire, and two crews were sent to the scene.