The blaze ripped through the property early on Thursday, leaving six siblings motherless and grieving the loss of an 11-year-old brother.
The victims were named by Stuff as 11-year-old Kelly Kerr and his mum Kelly Kemble Kerr.
In a statement yesterday afternoon Detective Sergeant Mark McCloy said the pair’s bodies had been taken to Christchurch where a post-mortem examination was conducted.
He said police and specialist investigators from Fire and Emergency New Zealand (Fenz) conducted a full-scale scene examination over the weekend, and concluded the blaze was not suspicious.
Fenz district manager Julian Tohiariki said the fire was caused by a heater coming into contact with flammable material, likely bedding.
The house had no working smoke alarms at the time of the fire, he said.
"This was a tragedy for the family and our thoughts are with them and the community of Manapouri at this difficult time."
Fenz was again reminding the public of the steps to take to be fire safe this winter.
"A fire can be un-survivable within just three minutes which is why it’s so important to get that early warning of fire from your smoke alarms.
"You can’t smell smoke when you are asleep", Mr Tohiariki said.
This was why people needed to make sure they had working smoke alarms in all bedrooms, hallways and living areas — including caravans and sleep outs.
"Check they are working by pressing the button each month. Now is also a good time to make sure your family has a three-step escape plan.
"It is important you keep flammable materials, such as clothing or bedding, at least 1m from the heater or fire."
