11-year-old boy and mother killed in Manapouri house fire

Neighbours desperately tried to save an 11-year-old boy and his mother who died in a house fire in Southland's Manapouri, police say.

Their bodies were found by specialist search teams combing through the ruins, after the blaze broke out in View Street at 3.40am on Thursday.

Police earlier said other people remained unaccounted for, but they were now satisfied no-one else was at home at the time of the fire.

A man who also lived at the rental property was away at work, police said.

Detective Sergeant Mark McCloy said officers were speaking to neighbours who tried to rescue the woman and her son.

"Neighbours at the property attempted valiantly to gain entry to the burning house, but they were unable to and contacted emergency services," he said.

The house was destroyed, McCloy said.

"We had to get a crane in yesterday to remove what was left of the roof to allow our scene team to get in," he said.

Due to the significant damage, this would take time and the scene examination would continue through the weekend, he said.

Police were still treating the fire as unexplained and were working with fire investigators to establish the cause.

McCloy said police and Fire and Emergency staff would continue examining the house over coming days.

Support was being offered to North Island relatives and local iwi had blessed the property, he said.

"The thoughts of everyone involved are with the victims' whanau, who are being supported at this tragic time.

"Our hearts go out to the family."

Fiordland councillor Sarah Greaney said people in Manapouri would be shocked and saddened by the deaths.

"We are a small-knit community, both in Manapouri and Te Anau, so when events like this happen they do send a ripple through the community," she said.

"These things do come out of the blue and they are unfortunately great reminders of how precious life is."