A couple found dead in their Canterbury home both suffered a single gunshot wound, police say.
The pair - a 77-year-old man and a 63-year-old woman - were found dead when police were called to a house in Kaiapoi, just north of Christchurch, yesterday afternoon.
Police are not looking for anyone else in connection to the deaths.
Murder-suicide was one possible scenario being considered by police, said Detective Senior Sergeant Tony Hill said.
Asked if that was the most likely scenario, Mr Hill said: "It certainly isn't one of the stronger indicators at the moment."
Mr Hill said the sequence of events seemed clear.
"But there's still a considerable amount of work to be done to confirm the facts that are before us at the moment. Over the course of today and probably the next two or three days we will try to corroborate those as best we can."
There was no indication of previous violence in the home, or matters of serious concern that had come to police attention.
Kaiapoi is amongst the worst hit areas from the recent Canterbury earthquakes - with almost 1000 properties having to be abandoned because of quake damage.
Ten months ago two elderly siblings Bob and Joan Cattermole died in their Kaiapoi home, and the stress of the quakes was considered a factor.
Post mortem examinations will be carried out today on the couple found dead yesterday.
The matter will be referred to the coroner.
Meanwhile a 54-year-old man has been charged murdering a woman who was found dead in the Christchurch suburb of Spreydon yesterday.
Police found the body of the 47-year-old woman after they were called to Cobham Street house at 5.30pm.
Detective Senior Sergeant Greg Murton said the man is due to appear in Rangiora District Court this morning to face a murder charge.
He said a post mortem on the woman would be be carried out later this week.
A scene examination at the property where she was found was expected to continue for another few days.
The woman's identity would not be released until next of kin had been notified of her death, police said.