Jealousy over a new relationship may have prompted an attack that left a man dead, a woman in an induced coma and sparked an international manhunt.
The dead man, Kenyan Stephen Mwangi Maina (38), suffered "significant injuries" when attacked early on Saturday at an Avonhead, Christchurch, house.
The woman, Lydiah Muthoni Munene (34), also a Kenyan, suffered serious head injuries and may remain in a coma over the next couple of days.
Police said the attack appeared to have taken place about the same time Ms Munene's estranged husband, Samuel Ngumo Njuguna, came to the house and took their two children away with him.
The pair were found in bed on Monday, but police would not comment on whether they were clothed.
Mr Njuguna (39) is believed to have travelled to Kenya.
Police have made contact with the Kenyan consulate in Canberra and the Crown Law Office in Wellington, with a view to possibly seeking the extradition of Mr Njuguna.
Asked if Mr Maina and Ms Munene were in a romantic relationship, and if this could have triggered the attack, Detective Inspector Greg Williams said: "We can't rule that out, but . . .
I'm not going to comment any further on that at this point in time".
Police had interviewed the children, aged 9 and 13, but Det Insp Williams would not disclose what they had been able to tell police.
The children are now in the care of Christchurch's small Kenyan community.
A weapon was used in the attack, and police said they had a good idea what they were looking for, but would not discuss it publicly.
Mr Njuguna approached a travel agency about 9am on Saturday about leaving the country, and left for Kenya the following day, flying via Auckland, Sydney and Bangkok.
It is believed Mr Maina arrived in New Zealand about October last year, and had been working at a freezing works at Ashburton.
Police were speaking to his flatmate.
Det Insp Williams said he had been in touch with Mr Maina's family in Kenya to tell them what had happened.
He also had a brother in Australia.
"Mrs Maina, Stephen's mother, told us that was her third son that she had lost; so obviously pretty hard for the family."
Property owner Margaret Dawson said Ms Munene, a working nurse, was looking for a fresh start with her sons when she rented the Avonhead home from her about five or six weeks ago.
"I go there quite regularly, and I never saw anybody else there."
Mrs Munene was quiet, sympathetic, and interested in others - "ideal for a nurse, I thought".
While New Zealand and Kenya do not have an extradition agreement, it is understood the process will be made easier by both countries being members of the Commonwealth.