Police say they were alerted to a raging house fire in Franz Josef on Tuesday night when a woman called saying her partner was driving a bulldozer over their property and the house was ablaze.
Attached to the house was a mechanical workshop was also engulfed.
The woman had fled the scene to call police, who arrived at about 7:40pm. A neighbour, who did not want to be identified, told Newshub the woman came running to his place.
"A woman came down to us, she was pretty distraught and said that the place was alight and her partner was inside it.
"She was crying and she had lost one of her shoes. She was sopping wet because the sprinkler system had kicked in. She was really an absolute mess," he said.
"She said they had a fight, but that's all."
Her partner was thought to have a number of firearms wrapped in a blanket at the blazing property, police say. They also believed he was carrying a barrel of oil in the bucket of the bulldozer.
Local volunteer fire services arrived but the risk of guns and a barrel of oil by the inferno meant they couldn't get close until police had dealt with the man.
The man fled the scene, and enquiries are ongoing to find him.
"Police and fire worked together to ensure the safety of nearby residents and ensure that the risks to life and property were minimised," acting West Coast Area Commander Vicki Walker said in a statement.
They're investigating the cause of the blaze and are staying at the scene, she said.
The fire was put out at about 2:30am on Wednesday, and police say no one is at risk after the incident.
Police say an update on this investigation will be announced on Wednesday afternoon.