The sister of an Australian man shot dead in New Zealand says his family "don't know how to begin to put life together without him", after police charged a 23-year-old man with his murder.

Key points: Police allege a gunman demanded the keys before firing multiple shots into Sean McKinnon's van

Police allege a gunman demanded the keys before firing multiple shots into Sean McKinnon's van A 23-year-old man has appeared in court charged with murder

A 23-year-old man has appeared in court charged with murder Friends say the incident has left Mr McKinnon's fiancee "completely numb"

Victorian man Sean McKinnon, 33, was in a campervan with his Canadian fiancee early on Friday morning in Raglan, a surfing town in Waikato, when a man demanded the key to the vehicle.

Police say the man then fired several shots into the campervan before driving off in the stolen vehicle with Mr McKinnon inside.

Mr McKinnon's fiancee Bianca Buckley escaped and alerted police, sparking a manhunt. Mr McKinnon's body was later found inside the abandoned campervan, almost 80 kilometres away.

Sean McKinnon and his fiancee Bianca Buckley were in the campervan when a man demanded the keys. ( Supplied: Facebook )

The suspected gunman was arrested after police raided a property at Tauhei on the outskirts of Hamilton late on Friday night.

He appeared in Hamilton District Court this morning charged with murder, aggravated robbery, threatening to kill and driving disqualified.

His identity was suppressed and he was remanded in custody to face another hearing in the country's High Court on August 27.

Police have yet to find the gun used in the attack.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 32 seconds 32 s Australian man shot dead in campervan in New Zealand

McKinnon remembered as 'honest, cruisy guy'

Mr McKinnon came from a family of six siblings. Three of them travelled to New Zealand in time to be in court on Saturday.

His sister Emmeline said the family was devastated.

"Sean was a wonderful person and we loved him very deeply," she said.

"I was devastated to hear his life had been taken from him. The worst thing was telling my mother.

"He loved being over here, he loved the surf here, he loved the lifestyle and the place. He was very well-loved, he's a real character and we just don't know even how to begin to put life together without him."

Sean McKinnon's siblings Emmeline, Lachlan and Mary (left to right) are in New Zealand with Mr McKinnon's finance. ( ABC News: Josh Bavas )

She said the family was comforting Ms Buckley.

"Bianca is amazingly resilient and strong — I can't begin to understand what she's been through," she said.

"Obviously that was our first priority, to get over here and just let her know that we're supporting her.

"We're just really glad that she's alive."

Before leaving Australia, Ms McKinnon told New Zealand media she was haunted by thoughts of her brother's final moments.

"I feel sheer helplessness. As an older sister I wish I could have been there to defend and protect him," she said.

"It's a horrible thought to know he was alone when he died."

A map showing Whaanga Road, Raglan in New Zealand where an Australian man was shot dead while sleeping in a campervan. ( ABC News )

Port Campbell in complete shock after death of 'beautiful young man'

Mr McKinnon grew up in Nirranda near Port Campbell on Victoria's Great Ocean Road.

Friends say the town embraced Ms Buckley, who spent last summer working at a cafe on the Port Campbell foreshore.

"They were perfect together — they were both free spirits," Port Campbell Boardriders Club president Olivia Tatungi said.

She said Mr McKinnon, who she first met when he was 13, was "truly unique".

"I was in year 7 when Sean arrived and he was like nothing we'd ever seen before, " Ms Tatungi said.

"Every time you met Sean it was just like a memorable moment."

Ms Tatungi said the pair and their friends would catch surf breaks behind the Port Campbell pier and try to ride the perfect wave.

"He loved the water, it was his life," she said.

"He had a fantastic [surfing] style that looked like it came out of the 70's, he just rode the wave from his heart instead of thinking he should look a certain way."

Sean McKinnon was remembered by friends as being "truly unique". ( Supplied: Facebook )

She said surf, music and the ocean were his greatest passions.

"He just had that unique ability to stay in the moment, so many of us go to yoga or try these things but Sean just embodies living in the moment,".

Ms Tutungi said Ms Buckley had been left "completely numb" by the tragedy.

"She's lucky to have survived, but she's got a situation to deal with that no-one knows how to cope with," she said.

Port Campbell's Mayor Neil Trotter said the community was in complete shock.

"Sean was such a peaceful beautiful young man. I just can't quite fathom the fact that he's met a violent death," he said.

"The McKinnons were one of the first families in this area, everyone knows them and it's just really devastated us all."

Corangamite Shire Councillor Simon Illingworth said he had spent countless hours surfing alongside the young man around Port Campbell, and had know him for about 15 years.

"I just cannot believe that such a nice person could have their life finished like this," he said.

"He was just so lovely … such an honest, cruisy guy.

"He used to share waves in the surf and he was so courageous in big waves."