Update, 8.30am: The cause of a fire which damaged a Moerewa home has been ruled suspicious but undetermined.
The blaze, on Otiria Rd just before 8am on Wednesday, damaged the rear of the house and had started spreading into the ceiling cavity.
The occupants had left for work but a neighbour spotted the smoke and doused the flames with a garden hose until the Kawakawa Fire Brigade arrived.
Fire investigator Terry Baylis traced the origin of the fire to a rubbish bag on the back patio. The home owners were adamant no cigarette butts had been placed in the rubbish, and there was nothing in the bag that could have ignited spontaneously.
Although no one had been seen at the address it appeared the rubbish bag had been moved after the occupants left that morning.