Police in Whanganui have launched a homicide investigation following the death of a baby girl.
Hinekawa Topia, who was aged two months, died of non-accidental head injuries in Wanganui hospital on Thursday.
She was driven to the hospital by her parents just before 1pm - she was not breathing and attempts by her father and hospital staff to resuscitate her were unsuccessful.
Hinekawa was one of triplets and the other two baby girls, are in hospital to be medically assessed as a precaution.
Child Youth and Family have interim custody of the girls, along with a five-year-old boy.
Two houses, one in Whanganui and one in South Taranaki, have been subject to scene examinations by forensic experts.
About 20 police staff are working on the inquiry.
Detective Senior Sergeant Neil Forlong says Hinekawa recently stayed at both the family home and with extended whanau, and the police will be speaking to family and non-family members.
He says police still need to speak to more than six people.
Mr Forlong says Hinekawa's funeral was on Sunday.