Investigators are still outside a special education school in South Auckland where a woman was found dead on Saturday afternoon.
Police say the woman was found dead about 4.30pm at a "non-residential property" in the suburb of Manurewa.
On Sunday morning, a police tent could be seen near McVilly Road, adjacent to the BLENNZ Homai Campus.
Police detectives had arrived and a police drone could be seen flying around the area.
A neighbour said he did not see or hear anything until the police arrived, but told 1News he was "shocked" when he heard a body had been found.
He said police forensic teams had been at the site late into the night.
A post-mortem is underway, but the woman's death continues to be treated as unexplained, police said on Sunday.
Work is underway to confirm the woman's identity, which is a current priority for the investigation.
Investigators believe she is in her late teens or early 20s, so are asking the public to get in touch if they have a young family member or friend that has not been contact over the past day and this is out of character for them.
"It is important police do this, as there will be next of kin and loved ones that need to be advised of what has happened."
Police have begun examining CCTV footage from the wider area and a spokesman said this will form an important part of the investigation going forward.
One ambulance and a staff manager were called to the scene, a St John spokesperson earlier told 1News.
Anyone with information can contact Counties Manukau CIB on (09) 261 1321, referencing Operation Casting.
People can also contact 105, quoting the file number 210911/6094 or Crimestoppers anonymously on 0800 555 111.