A newborn found dead at a south Auckland recycling plant this week was a baby girl, the police say.
The infant's body was discovered on Monday evening at Visy Recycling on Victoria St in Onehunga, and police on Tuesday revealed it was moved there via a rubbish truck.
A post-mortem carried out on Wednesday confirmed the baby was a girl born at full-term, though police say her ethnicity remains "undetermined".
"We are not going into any specifics around the findings of this post-mortem but it has caused police to have further concerns for the welfare and health of the child's mother," said Auckland City Police Detective Inspector Scott Beard.
"Since our appeal yesterday we have received very limited information and it has not led us to finding the baby's mum."
Det Insp Beard said police had carried out a scene examination and been looking at CCTV footage, which had led to the discovery of some "items of interest" - including a bag and some clothes - which they will release photos of on Thursday.
Until then, he urges anyone with information to get in touch with police urgently.
"We must find the mother of this child and make sure she is okay. It may be that she requires medical treatment and without it, there could be serious consequences," he said.
"We are continuing to make a number of enquiries and we will be carrying out DNA testing in the hopes this might lead us to the mother or at least to someone who might know who she is."
Anyone with information can contact 105 quoting file number 210816/2825. Alternatively, information can be provided anonymously via Crime Stoppers on 0800 555 111.