Detective Sergeant Mark McCloy confirmed to the Herald today the victims were a young boy, 11, and his mother.
He said this afternoon a couple and a child had been living in the rental house, but the man was away working when the fire took hold.
Police are satisfied no one else was at the property when the fire took place.
“A crane was used remove the remaining sections of roof to allow specialist investigators from Police and Fire and Emergency New Zealand to enter the home,” he said.
“Importantly, our hearts go out to the family. Events like this are tragic, and we are ensuring there is appropriate support in place for those affected by this terrible event.
“Emergency services were called to the property about 3.40am on Thursday and were alerted that people may still be inside. Since then, a methodical investigation has been under way to account for the occupants of the address.”
“The thoughts of everyone involved are with the victims’ whānau, who are being supported at this tragic time. We would also like to thank members of the community for their concern and care,” McCloy said.
“Police will work alongside Fire and Emergency New Zealand to conduct a scene examination and inquiries over the next days.
“The cause of the blaze continues to be unexplained.”
It’s understood a mother and her child lived at the property, while another man lived in a sleep-out.
Southland Mayor Rob Scott said: “It is just absolutely tragic for the tight-knit community there and my thoughts go out to the family and everyone else affected.
“I also want to thank the amazing volunteers who worked to get the fire under control.”
Fenz crews from Manapōuri and Te Anau rushed to the single-storey home.
Fenz said the house was well alight when crews arrived.
Hato Hone St John was also in attendance.
“We responded with one operations manager, but our services were not required,” St John said.