Firefighters from the Mossburn and Lumsden stations were sent to the property in the Mossburn area just after 10.30pm and a room in the house was well alight when they got there, a Fire and Emergency New Zealand (Fenz) spokeswoman said.
"No one was at home at the time," she said.
A police spokeswoman said the fire was in Wreys Bush-Mossburn Rd, a guard was at the scene overnight and police would be making inquiries.
Fire investigator Murray Milne-Maresca was at the scene this morning.
"The fire was witnessed by a passer-by on the main highway," Mr Milne-Maresca said.
The three-bedroom house was on a farm and it was severely damaged and now uninhabitable, he said.
"It is under investigation as a suspicious fire."
Gore house fire
The house fire was one of two from last night Mr Milne-Maresca was looking into.
The other was in Gore and it was not suspicious, he said.
Firefighters from Gore and Mataura were called to a property just after 6pm last night, a Fenz spokeswoman said.
The occupants of the house were able to get out and the house was "fully involved" when firefighters arrived, she said.
Mr Milne-Maresca said the fire started in a bedroom at the back of the house and he was still investigating the cause.
The occupants had noticed smoke and could see flames in the bedroom, he said.
"They had working smoke alarms and everyone got out safely."
This included their black labrador, Albie.
