A man has died and a woman has been rushed to hospital in a critical condition after an incident in Glen Eden, West Auckland.
Police are at an address on Pisces Rd, Glen Eden, with emergency services being alerted to the event about 3.44pm.
Police are not seeking anyone else in connection with their ongoing enquiries.
A neighbour, who the Herald has chosen not to name, said guests had been attending a birthday party at the house earlier today.
People from the house had approached him this afternoon, asking if he'd seen anything unusual.
"They were asking me did you see anyone come to [the house]," he said.
One of the people, a woman, then told him her brother had been killed.
He hadn't seen what had happened.
It was the first time he'd heard of trouble happening at the house, the man said.
Inspector Brett Batty of the Waitakere Police said he was dealing with a grieving family and would not be making any further comment about the incident at the scene.