"Post-mortem examinations have been carried out today and police will be referring the matter to the Coroner," he said.
Police can also name the two, who were a mother and her newborn baby.
They were: Emerald Waiari Tai, aged 27, and Tanatui Samuels, aged 3 days.
"This event is an absolute tragedy and police send their sympathies to the family at this difficult time," said Sutton.
Tributes have already been posted online for Tai, who was known as Emz.
"Still coming to terms with you not being around," said one friend.
"Your laughter, your perkiness, your love and you just being you.
"Knew we should of came around lastnight but we got lost and ended up cruising back home.
"I just cant believe it."
According to her Facebook page Tai was from Opotiki and went to school in Tauranga.
She listed "full time mummy" as her current job but stated she had studied in the travel and tourism sector.
It is understood Tai is survived by several other young children.