Police are investigating a suspicious house fire that killed a woman and left two children in serious condition in Hamilton.

Neighbours were woken by the fire in Fairfield about 3.45am as flames engulfed the state house.

Friends of the family said seven people were living at the house including two children taken in when their mother died last year.

A woman, her partner and three teenagers were also believed to live at the house.


Neighbour Rita Didovich said she was woken by her dog barking and as she went out to quieten him down she spotted flames coming from the house.

"Boy were those flames high. It was well alight. The lounge windows, bedroom windows and the rooms at the end of the house where the flames were coming out of were high flames ... They were as high as the roof, easily.''

Ms Didovich also saw a woman sitting on the other side of the road rocking back and forward as the flames took over.

Another neighbour said she heard a man and woman yelling for help. She heard a "big bang'' as the glass shattered.

"It was loud, all the windows burst,'' she said.

Neighbours said they heard a car screeching off from the house after the fire took over.

Friends said the family, who moved into the property two years ago, was being harassed.

Hamilton Detective Senior Sergeant Karl Thornton said one person - who neighbours believed to be the mother - died in the house

while two adults and two young children were taken to Waikato Hospital.

The other occupants managed to escape.

"After fire fighters extinguished the blaze a person's body was found inside the house. As a result an investigation into this unexplained

sudden death is now underway,'' Mr Thornton said.

Police and fire services had launched an investigation into the fire and part of the road remained cordoned off today.