The father of the children - believed to be in his 30s - was described as a local businessman and records indicate he had owned the property wrecked in the blaze for nearly 10 years.
Company Office documents show he has run businesses since 2018.
A forensic pathologist will work alongside police investigators on a “complex scene examination” of the damaged property.
Manawatū area commander Inspector Ross Grantham said police are waiting for the completion of the scene examination to piece together the circumstances that led to the blaze.
“This won’t be a fast-moving operation; it will be methodical and take time to work through what is a pretty complex and hazardous scene.”
Grantham said there were concerns about the stability of the remaining structure and they needed to make sure staff were safe while they worked.
“While the investigation is ongoing, police are also providing wrap-around support to the family and neighbours,” Grantham said.
“I want to acknowledge the support we’ve had from the Sanson township and wider Manawatū community.
“Events like this hit at the hearts of our communities and we are doing everything we can to answer the many questions around this devastating incident.”
Grantham said further information will be provided when it becomes available.
Ford called the tragedy “a sore hit” for the tight-knit town.
“This is going to hurt our community - we are a caring community who will feel this deeply.
“It’s a tragedy, and our hearts go out to the family and the friends of the deceased. We hope that they’ll accept our sincere condolences.
“[Sanson] is an important part of our Manawatū community. We must thank our police and our fire and emergency, and all the responders.”
A person who lives near the fire said it was “very upsetting”.
“All I can say is they are a lovely family and neighbours.”
The neighbour described the children at the home as “happy, sweet kids”.
Police earlier confirmed they were not seeking anyone else in relation to the fire.
Grantham announced the deaths on Saturday evening.
The Herald understands police had been searching for three children after the blaze broke out.
Fire and Emergency NZ handed the scene over to the police who put a guard in place overnight on Saturday.
The large blaze closed State Highway 1 between Phillips St and Speedy Rd, police said.
Firefighters from the Bulls, Rongotea, Manawatū, Whanganui, Marton and Palmerston North brigades were called to the blaze.
Fire and Emergency New Zealand declined to comment when approached by the Herald.
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