A house at Titahi Bay, north of Wellington, in which two women were found dead late last month has been badly damaged in a fire.
The Morere St house was extensively damaged in the blaze early on Sunday morning, which police are treating as suspicious.
The Fire Service says neighbours phoned 111 when they saw the fire just after 6.30am, and the house was well alight when firefighters arrived.
Joelene Edmonds, 21, and her 16-year-old boarder, Jashana Robinson, were found dead in the home on 26 June.
Detective Sergeant Shane Rongonui of Porirua police says the uninhabited Housing New Zealand house sustained extensive heat, smoke and water damage in the blaze.
He says officers are speaking with a number of people who may have wanted the house burned down, and the scene is being examined to determine if an accelerant was used.
Detective Sergeant Rongonui says the fire put neighbouring properties and people's lives at risk.
Ms Edmond's former partner Joseph Ogle, 28, has been charged with murdering the women, and breaching a protection order.
He is in custody until he reappears in court next month.