Southern District Commander Superintendent Paul Basham, left, and Acting Area Commander Southland Area Inspector Mike Bowman speak regarding the Invercargill shooting.

An Invercargill policeman allegedly shot dead his wife, tried to kill the man she was with, then handed himself in at the local station.

Constable Ben McLean's alleged Anzac Day attack could be the first of its kind in recent New Zealand history involving a serving police officer.

Verity Ann McLean died in the shooting. Garry William Duggan, who suffered several gunshot wounds, phoned emergency services at 8.19pm on Tuesday.

FACEBOOK Verity and Ben McLean, pictured in 2016. Ben McLean allegedly fatally shot Verity and wounded Garry Duggan.

Ben McLean, 47, was injured in the incident, though police have not said how.

The constable was in Southland Hospital, where a bedside court hearing took place on Wednesday afternoon.

Wearing a grey T-shirt, white trousers and with no visible injuries, he made no plea to murdering Verity McLean and the attempted murder of Duggan. He was remanded in custody to May 18.

FACEBOOK A friend says Verity Ann McLean was "a lovely lady": "[She was] a caring, happy, great mum."

A friend of Verity McLean, who did not want to be named, said she was "a lovely lady".

"[She was] a caring, happy, great mum," she said.

At a media briefing on Wednesday night, Southern District Commander, Superintendent Paul Basham said the town's community, including police, were "shocked and dismayed" by the incident.

FAIRFAXNZ McLean graduated from police college in 2007 before joining the Southland District Police.

He confirmed Ben McLean was off-duty at the time. He said the three people knew each other.

The two victims were residents at the industrial building on Otepuni Ave in the suburb on Newfield.

Stuff understands Duggan and Verity McLean were in a relationship.

Ben McLean "handed himself in" at the Invercargill Police Station about 40 minutes after the shooting.

A firearm was recovered at the scene. Basham would not say what kind of gun it was, but said it was not a police issue weapon.

"This is obviously a huge tragedy for everyone involved. We are dealing with three different families who are affected," Basham said.

ROBYN EDIE/FAIRFAX NZ Police were today examining the shooting scene.

"We are also supporting police staff ... who are naturally very shocked and dismayed at what has taken place."

Basham promised a thorough, impartial investigation. Senior investigators - Detective Inspector Steve Wood from Dunedin and Detective Superintendent Peter Read from Canterbury - were in Invercargill to help lead the inquiry.

"I fully understand the shock this incident has caused … while devastating, this is a one-off event and we cannot recall a similar tragedy like this in recent times to allegedly involve a serving police officer."

ROBYN EDIE/FAIRFAX NZ The Otepuni Ave address where a shooting took place in Invercargill on Tuesday night.

He asked anyone with information to come forward to help police "piece together" what happened.

"Obviously Invercargill is a pretty tight community."

Ballistic forensic specialists would reconstruct what happened, including the number of shots fired, he said.

AMBER-LEIGH WOOLF/FAIRFAX NZ Police cordoned off Otepuni Ave in Invercargill after the shooting.

Basham would not say how the shooter went to the scene. One resident saw a man on a bicycle who changed his clothes and seemed to be "up to no good".

Duggan, who is in his late 40s, was understood to be in Dunedin Hospital in a stable condition.

COUPLE HAVE THREE CHILDREN

Ben McLean, 47, was married to Verity McLean (nee Barber), who died in Tuesday night's shooting. The couple have three children under age 20.

He graduated from the Royal New Zealand Police College in Porirua on December 18, 2007 before starting work in Invercargill a few weeks later.

He has been part of the Southern District policing team since. He has worked on road policing cases and road safety campaigns.

JONATHAN MILNE / FAIRFAX NZ Police were inspecting three or four vehicles parked at the back of the property in question.

He previously worked as an administrator for Geographic Information Systems.

Ben McLean owns two semi-rural neighbouring properties in the suburb of Tisbury. One of the properties was listed as the couple's residential address.

His mother, Mary, lives next door.

JONATHAN MILNE/FAIRFAX NZ Forensic staff were on hand at the taped-off scene following the shooting.

When asked what might have led to the shooting, his mother said, "It's a very, very long story".

"I'm holding up OK, I've got a lot of friends and family."

She did not know how her son was.

Otepuni Ave remained closed on Wednesday morning with a cordon in place. Security guards were parked outside the property.

Property owner Phil Brocks said the victims lived in a property he owned at the site. He said the people involved were not linked to the businesses there - Fencing Around and Shuttleworth Electrical.

Brocks knew the occupants, but said he was not in a position to say anything as he was helping police with their investigation.

Shuttleworth Electrical owner Marilyn Greenwood did not know the victims, but was aware people were living at the address.

The Police Association refused to comment.

'UP TO NO GOOD'

Earlier, resident Terry Brown said he saw a man cycling on Otepuni Ave who seemed to be "up to no good".

Brown saw the man from his window.

"I set eyes on him and got suspicious of him."

Brown said the man stopped his bicycle near the train tracks on Lindisfarne St and changed clothes.

"He took his jacket off and then put another one on," he said.

"Then biked down Otepuni Avenue."

Brown said the clothes he wore were dark brown, or black.

"I was so sure that he was up to no good."

Police were seen searching nearby properties and vehicles.

A witness saw an ambulance rushing to the area.