It was a house for men to hide from society while alive, and last week police confirmed it was also the place to hide a murder.

Someone managed to keep that secret for at least a decade.

The Mt Eden property beneath which human remains encased in concrete were found on January 31 last year is now officially being treated as a homicide investigation.

The bones were on September 4 identified as the house's past owner David Stanley Hart who for decades, until about 2004, ran a ramshackle boarding house out of the weatherboard double-story building.

A rotating scruff of five or six men constantly filtered through the cheap, cash-only lodgings, rarely settling for long.

Ex-crims and elderly alcoholics were the typical clientele.

On announcing the elevation of the investigation to a murder, police noted the extreme difficulty of the case obscured by 15-odd years and the social isolation of the tenants.

"At this time, we are not able to provide a cause of death. Police do regard the death as suspicious and it is being treated as a homicide," a police spokesperson said.

In September, when Hart was identified, police said they had spoken to a number of people in New Zealand and overseas who had lived at the Marlborough St boarding house.

They were interested in anyone who had contact with Hart from March 2004 onwards.

While the investigation's elevation to a homicide may appear a relatively obvious development on the surface, several others who knew Hart had their own more hopeful theories on what had transpired.

Police are now officially treating the human remains found on Marlborough St, Mt Eden, Auckland, in January 2020 as a homicide. Photo / Alex Burton

An old acquaintance from Blackball on the West Coast, Neville Sheehan, was convinced Hart had just permanently moved to Australia, where he used to regularly travel in the '70s and '80s to gold mine with his brother - who has since died of cancer.

Marlborough St neighbours and the property's current owner Peter Marsden speculated the dysfunctional boarders at the house decided to bury Hart after finding him dead as the official outlets for reporting a death were not the marginalised tenants' style.

But police are not so optimistic.

The Herald can now reveal fresh details about Hart, who would have been 80 if he were alive today.

Neighbours who have lived on Marlborough St for 50 years had no idea what Hart did for a living or how he came into possession of the inner-city property.

However, it is now understood Hart was employed as a tally clerk on the Auckland Waterfront during the '70s and '80s.

A colleague of his there, Kevin Webb, said Hart's nickname was "The Gold Digger".

"Dave was an interesting person. He thought he knew everything about anything and would rattle on for hours," Webb said.

"One thing he used to talk about was prospecting for gold in the South Island which he had done on annual leave.

"He claimed he could make more money panning for gold than what he earned as a tally clerk, which was pretty good in those days."

It was noted by one past resident of the Marlborough St boarding house, who has spoken to police several times over the case, that there was "tension" between D'Angelo and Hart.

The ex-lodger characterised both men as "extremely eccentric".

D'Angelo - also known as George Nathan Gabriel Ormsby - died at the Marlborough St property on September 26, 2016.

Accounts of D'Angelo, who took over control of the boarding house once Hart disappeared somewhere in the 2000s, are vastly contrasting.

"He was always okay to me but he was always a bit weird. Extremely weird," the past resident said.

"He used to wear sunglasses and gumboots the whole time.

"Some of the stuff he said you just shook your head. Like, okay Gabriel, good night, bye. I saw him in the pub years after I left and I asked him how Dave was.

"He said 'oh yeah Dave I haven't heard from him'."

D'Angelo also had an association of sorts with the musician Don McGlashan.

McGlashan confirmed to the Herald he first met D'Angelo in the mid-'80s when he was assisting inmates at the Paremoremo maximum security prison in Auckland.

"He was an intelligent man," McGlashan said.

"He seemed like the kind of guy that had things gone better for him in his life, he might have actually been a fulltime professional musician."

The other specks of information that can be gleamed of Hart's life are confusing.

Murray Goldings, 46, has lived on Marlborough St his entire life and provided an
inadvertent summary of Hart's presence in the neighbourhood.

"He was sort of a bit of a loner. He was there for many years by himself. There was only him and then all the boarders came later on," Goldings said.

"There were rumours he went to Australia and there was another rumour he had dementia and had gone to a home somewhere. I reckon it would be over 10 years ago.

"He disappeared, and no one knew why."