A driver has died and their two passengers have been badly injured in a crash after initially fleeing police.
Acting central district commander Inspector Clifford Brown said a stolen ute, wanted in connection to a robbery in Ōtaki on Friday evening, was signalled to stop just south of Levin shortly after 10.30pm.
Police pursued the ute but abandoned the chase "within several minutes" due to the manner of driving.
The ute continued heading south "at speed" on State Highway 1, and about 10.50pm was spotted turning back onto the highway from Waikanae, heading north in the southbound lane.
Fifteen minutes later, the ute collided head-on with another vehicle, just south of Lawlors Road.
The ute's driver was pronounced dead at the scene.
The two other occupants of the crash were seriously and critically injured, while the four occupants of the other vehicle were moderately and seriously injured.
The man in critical condition remained in Wellington Hospital on Saturday afternoon.
A motorist has told RNZ two officers were standing by the southern on-ramp to the expressway at Ōtaki during the incident but he was still let on.
Gaige Mattila said he was driving to Paraparaumu when a vehicle came rushing towards him in the wrong lane.
"This vehicle with high beams on came flying past me. I had to slow down and move over because I was unsure if they were going to swerve into me, I didn't know what their intentions were."
He said he did not see the crash happen.
Posting earlier on social media Mattila said: "My life... flashed before my eyes going down the straight of the expressway.... I'm sorry [what] happened to these people, they must have been a minute behind me. I almost was the one in the head-on, I hope they are okay."
Brown said the serious crash unit attended and the incident would be "fully investigated".
Police had also referred the matter to the Independent Police Conduct Authority, he said.
"An outcome like this is never something police wants, and our thoughts are with those in the other vehicle who were needlessly injured."
Potential charges against those in the ute would be considered "in due course", he said.