Police were called to house on Ayr St, Riccarton, shortly before 6pm yesterday and found the pair - a woman and man - dead in different rooms.
They said this afternoon that they were "not seeking anyone else" in connection with the deaths.
However, they were not in a position to give any further details.
Stuff is reporting that the two are believed to be a mother and her adult son.
Specialist police including forensic teams are at the scene and detectives are working to piece together what happened.
Police will not be in a position to name the victims until a formal identification process has been completed.
They thanked the public for their help but would not be drawn further on the case today.
Residents woke up to the police investigation on their street this morning, and detectives were going door-to-door asking for information.
The house - on the corner of Ayr Street and Mona Vale Ave - appeared very closed up this morning with all the curtains drawn.
The mailbox is full of uncollected circulars and a red Toyota Current sits idle in the driveway, covered in moss and lichen.
A nearby resident told The New Zealand Herald they had not seen anyone at the property since the current owner moved into the neighbourhood last October.
A woman who lived several houses down from the scene told the Herald she heard police arrive last night and suspected something like this might have happened.
"The way the police were acting I guessed something like this had happened, but I hoped it hadn't," she said.
She said she only vaguely knew the people that lived in the house.
