Police are investigating the homicide of a 71 year old man in block of flats in Jackson St, Petone.

GRAPHIC WARNING: This story will upset some readers.

The man decapitated during a homicide in Lower Hutt was suspected to be involved in the sale of synthetic cannabis.

Frank Tyson, 71, died in a block of flats on Jackson St, in the suburb of Petone, on Friday night. A neighbour told Stuff on Monday morning there was a gathering at the apartment at the time.

FACEBOOK Frank Tyson, the man thought to be the victim of a homicide at Jackson Street flats in Petone. Neighbour's said Tyson was known to drive a "ghetto taxi'' for a fee.

Detective Inspector Shane Cotter would not speculate on any potential motive for the killing on Monday, but confirmed Tyson was decapitated, and neither he nor a 41-year-old man arrested on Saturday were gang members.

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A witness to the homicide's aftermath, who did not want to be named, told Stuff that gang members and associates were in attendance at a gathering at the apartments.

ALEX LIU/STUFF Forensic investigators at the Jackson Street apartments in Petone where a man was beheaded.

They had planned to rob the victim of homemade synthetic drugs and about $10,000 cash he had made from selling them, the witness said.

The victim was heard repeating the line, "this is the last thing I have to do before I die", the witness said.

Police, including armed officers, arrived soon after.

ROSS GIBLIN/STUFF Police talk about the homicide investigation at two apartments in a Petone HNZ complex at the centre in December. Eugene Baker has since pleaded guilty to the murder of Frank Tyson.

A 41-year-old man was arrested on what police say were unrelated charges of causing wilful damage and drug possession. He is due to reappear in the Hutt Valley District Court on Tuesday.

The witness, who did not want to be identified, said she was told the decapitation happened in the "old school" way.

"[The victim] seemed like a really depressed person but he was nice to other people ... He was really kind."

ROSS GIBLIN/STUFF Police are investigating the homicide of a 71-year-old man in a Lower Hutt block of flats. One of the flats under investigation has a smashed glass door.

A woman who lives in the area - known locally as "the Bronx" - said Tyson would drive people to score marijuana and synthetics for a small price.

She said there was tension between Tyson and a man who had recently moved into the neighbouring apartment block.

The man had been beaten up by gang members the day before Tyson's death, she said.

A neighbour said Tyson was a "good bloke" who would "drive a ghetto taxi, for a price."

The man said Tyson had lived at the flats for about 20 years, and was well-known for dealing synthetics.

"What happened to him comes with the territory but apart from that he was a good bloke.

ROSS GIBLIN/STUFF The apartments in the Lower Hutt suburb of Petone, where the homicide took place.

"I couldn't have wished that on my worst enemy - even though he was making money he didn't deserve to die like that."

Hutt City Councillor and Petone resident Tui Lewis, who knew Tyson, said neighbours had raised with her that he was involved "somehow" in the sale of synthetic cannabis out of the Housing New Zealand property.

"The sad thing is, if it wasn't Frank somebody else is going to be doing it."

Tyson was a vocal member of the community, she said.

"He'd been part of the community for more than 20 years. While I've been on council, Frank was never afraid to say this is what we need, this is what we can do and Frank wasn't afraid to speak up. He always had a strong point of view.

"The last time I was with Frank we started a community stream clean,. There's a beautiful historic stream, Te Mome stream that runs behind the apartments and he was there and he contributed to the Facebook page, and was keen to have all his photos up ... he'd go overboard with his photos."

Lewis said she did not think Tyson was a substance abuser, and was "definitely never" gang-affiliated.

She thought he would have sold drugs to make ends meet.

* This story previously contained information from a witness that Stuff now understands to be incorrect, and the story has been amended to reflect this.