UPDATED: 3.30PM

A 44-year-old man died on the way to hospital after being shot once in the shoulder by a police officer.

The man was carrying a machete as he approached a police officer alone in a police car and had been involved in an earlier domestic incident in Waikanae, Acting District Commander for Wellington, Superintendent Steve Kehoe said.

"The information I have is staff acted professionally, appropriately and in accordance with policy, and on that basis the staff have my 100 per cent backing and support," Kehoe said.

There are several investigations into the police shooting, including one by Independent Police Conduct Authority.

The situation started with police being called to a domestic incident between a man and a woman in Waikanae, north of Wellington. A knife was reported to be involved in that incident but the woman was not harmed.

The man's vehicle was found around Mana Esplanade at 12.30am on Sunday and the man approached the patrol car with the machete.

Kehoe wouldn't comment on whether a warning was given before the police officer fired the shot.

Another police officer witnessed the incident.

The man was given first aid at the scene and paramedics were called.

Police have recovered a machete and there was air rifle in the man's vehicle.

The man was known to police.

Tasers are available to staff on duty, Kehoe said. He said situations required staff to make an assessment of the threats they faced.