"Those in the vehicle assisted police with their inquiries, however at this stage, no arrests have been made," said a police spokesperson.
"The circumstances of how the victim received their injuries are not clear and the investigation is ongoing."
The circumstances of a serious incident in New Lynn last night are yet to be determined. Photo / Hayden Woodward
One neighbour reported hearing a scream believed to be from a woman during the time of the incident.
The neighbour, who lived across the Avondale stream not far from the house where the incident unfolded, then heard sounds of the police helicopter and emergency services at the scene, but dismissed it, given how often those sounds were heard in the area.
A witness of the incident saw police move a man from the street to a nearby BP where he was treated by St John paramedics.
They said the scene was cordoned off as detectives began their investigations around a property in the cul-de-sac.
"A group of detectives were canvassing the outside of a home at the end of the cul-de-sac on McWhirter Pl, whist officers spoke to persons nearby taking statements."
Anyone with any information is asked to contact police on 105, quoting file number 220501/6118.
