Police say a victim of a serious assault in South Auckland is not expected to survive his head injuries.
The 56-year-old man and his sister, aged 57, were assaulted at house in Bolton Place, Otara, with a long stick and possibly other weapons on Wednesday morning.
The woman is in a serious but stable condition in Auckland Hospital.
Detective Senior Sergeant Dave Glossop says if the man dies, police will be treating it as a homicide.
The man they are looking for in relation to the attack is Patrick Young, 42, who is a stepson of one of the injured.
Mr Young left the scene of the attack in a white 1997 Toyota Corolla, registration WE4873.
Mr Glossop says Mr Young is known to police and should not be approached by the public.
Anyone who may know his whereabouts is asked to contact police.