David Tamihere spent two decades in prison for the twin backpacker murders he always denied committing.
The Crown's pursuit to convict him was, in part, formed around the "powerful" testimonies of three secret jailhouse informants.
They were known as "Witness A", "Witness B" and "Witness C".
Their evidence has been remembered as a vital part of the puzzle for the jury to piece together, and it led to Tamihere being convicted of both murders and sentenced to life imprisonment in December 1990.
But last year, in a rare private prosecution by "jailhouse lawyer" Arthur Taylor and well-known barrister Murray Gibson in the High Court at Auckland, one of the secret witnesses was found to have lied.
He was found guilty on eight perjury charges and not guilty of obstructing the course of justice, which pertained to a 1995 affidavit recanting his murder trial testimony.
That man who took the stand 27 years ago was Witness C.
That man is Roberto Conchie Harris.
The Herald has fought alongside other media outlets to unveil Witness C and can now reveal for the first time details of Harris' life and long criminal history.
This month, Harris dropped his bid to quash his perjury convictions at the Court of Appeal - opening the door for him to be named.
Taylor and the media had also been fighting against the Crown in the Court of Appeal to have Harris' identity revealed.
Today, Harris was unmasked as Witness C when Justice Christian Whata revoked his interim suppression order from the end of Harris' perjury trial.
The perjury case against him came nearly three decades after police had arrested Tamihere, later suspecting him of killing Urban Hoglin, 23, and Heidi Paakkonen, 21.
The Swedish tourists disappeared in April 1989 and had left their car at the end of the Tararu Stream road in the Coromandel Ranges.
Tamihere, who also has other violence convictions, including the 1972 manslaughter of 23-year-old Mary Barchamm, admitted stealing the Swedes' car but denied having ever met them.
Police arrested Tamihere after he absconded while on bail for sexually violating and threatening to kill a woman in 1986. He was living on the Coromandel Peninsula when the Swedes went missing.
Police connected him to the Swedes' murders after two trampers identified Tamihere as a man believed to have been seen with Paakkonen in the bush.
They said they saw a clean-shaven man or a man with a small moustache, however, Tamihere had a big bushy moustache at the time.
The mystery over whether he was the killer gripped the nation and sparked the biggest land-based search ever undertaken in New Zealand, but no bodies were initially found.
Despite this, Tamihere went to trial and Harris was listed as a secret Crown witness.
He was called to give evidence.
He told the court he met Tamihere while they were in prison during the 1980s.
He claimed Tamihere gave his own son Hoglin's watch.
He said Tamihere confessed to killing the Swedes.
Roberto Conchie Harris: A killer and a life of crime
Harris claimed he met Tamihere in prison while serving time for the murders of Northland couple Carole Anne Pye and Trevor Martin Crossley.
Pye's three children, then aged 10, 9 and 7, found their mum and her partner's bodies with gunshot wounds to their heads when they returned home from school on February 22, 1983.
Police tracked down Harris as the man who pulled the trigger and later that year he was found guilty by a jury in the High Court at Whangarei of their murders.
Then an unemployed crane driver, Harris would later describe in a statement to police how he shot Crossley in the back of the head before calling out to Pye.
As Pye walked past him, he said, he shot her too.
Harris said Crossley was still breathing so he shot him once more.
At his trial, Harris' girlfriend infamously testified that Harris had told her the killings were "just like having an ice cream''.
Harris' trial didn't go without incident either.
It was delayed after he was injured while attempting to escape from Mt Eden Prison in September 1983.
He was discovered outside the prison grounds after seemingly falling while climbing the perimeter wall and was treated for a broken hip and ankle.
His injuries also led to a controversial accident compensation windfall of $19,779, which angered John Pye, the father of Pye's three children.
In 1984 the children were each granted $500 by the Accident Compensation Corporation (ACC) for the killings.
However, Harris, who was serving his life sentence at Paremoremo Prison, was awarded the nearly $20,000 by ACC in May 1986 for the injuries sustained during his escape bid.
A specialist assessed his injuries as involving 49 per cent permanent partial disability, and thus entitled him to a payout.
ACC said at the time that because Harris was never charged and convicted for the attempted escape he could not be refused the payout.
John Pye told the Herald afterwards that it was "a big joke".
Harris later offered to gift some of his payment to Pye's children, but John Pye turned down the offer, while the government also closed the "legal fluke" which allowed Harris' payout.
"We could not take it on purely moral grounds, as we have said before, that no money in the world was going to bring back their mother," John Pye told the Herald.
Witness C has led a long life of crime.
His first conviction came in 1964 when he was just 15 years old.
When released on parole in 1995 for the Northland killings, he soon committed a serious assault and was recalled to prison.
Later in October 2008, he was found guilty of performing an indecent act on a young girl on the same day he was released.
He was sentenced to a further two years and three months' imprisonment.
A 2012 Parole Board decision, released to the Herald, referred to Harris' psychological report which assessed him as being at a high risk of reoffending but that something was "amiss" about his latest crime.
"He tells us that previously he had always confessed when charged with offending, which was true, and the fact that he denies this [latest offending] indicates that this time there was something amiss with the conviction,'' Parole Board chairman Sir David Carruthers said.
"He is assessed to be at high risk of reoffending and has done nothing to reduce that, and has no adequate release proposal to manage his risk at the present time.
"When he is seen again, we look forward to seeing a blemish-free time in prison," Carruthers said.
"Any misconducts or incidents, even with his eloquent explanations, simply do not ring true.
"Whilst he has a record of poor behaviour in prison, that mitigates against our considering him to have lowered his risk.''
Prison inmates: Harris and Tamihere
While both were incarcerated in the late 1980s, Harris said he met Tamihere for the first time - a meeting Tamihere denies ever happened.
Harris would tell the 1990 jury that his cellmate began talking to him about two young Swedish tourists.
Plastered on the inmates' cell wall was said to be a large map of the Coromandel.
"'The silly buggers were looking in the wrong place', or something to that effect," Harris claimed Tamihere told him, recalling their supposed interaction during his perjury trial last year.
"He told me he came across the Swedish couple in a Coromandel picnic area," he said.
Harris claimed that Tamihere told him, in detail, how he lured Hoglin in - to show him the scenery.
"I think he said at some stage [that] he knocked the guy off. He said at some stage he'd disposed of the body at sea, which I learned later on was not true," Harris said.
He also claimed Tamihere confessed details of the brutal killings and that he'd sexually molested Hoglin and tied him to a tree before attacking Paakkonen.
"All sorts of sexual debauchery you could think of, over a three-day period I think he said.
"I was disgusted. How he could be boasting of such things?"
Hoglin's body was eventually discovered by pig hunters in 1991 in bush near Whangamata, about 70km from where the murders were alleged to have taken place.
His watch was still on his body.
A pathologist concluded that Hoglin did not die from a blow to the head with a "lump of wood", as Harris had testified.
Paakkonen's remains, however, have never been found.
Harris' affidavit and 'police inducements'
With Tamihere serving his sentence, having exhausted all his options to appeal including to the Privy Council, Harris brought the case back to life.
He phoned then future Labour Cabinet Minister John Tamihere, David Tamihere's brother, three times from prison.
On August 25, 1995, Harris swore an affidavit effectively confirming that he lied and gave false evidence at Tamihere's trial.
There were "big offerings", Harris said in the affidavit, if he was interested in becoming a secret witness for the police.
One of the inducements was said to be a cash bribe of $100,000.
"I make this affidavit as I know that acts done and accepted by me prior to now affecting [Tamihere] were legally and morally wrong," Harris said in the legal document.
He said police had fed him the evidence about "the blood stains on the tent", which Tamihere had supposedly concealed in a hut or shed.
"I as (sic) told about sexual activities involving the female Swede after the male Swede's body was supposedly disposed of. I was told that a watch belonging to the male Swede was given by [Tamihere] to his son," the affidavit continued.
"I was told about trampers coming upon [Tamihere] and the two Swedes and that at such time the female Swede was visibly distressed. I may have been told also about a body being dumped at sea."
He said police wanted him to testify that "all of this had been told to me by [Tamihere]".
"It was the money I wanted," Harris said in the affidavit.
One of the other supposed bribes was for police to help its secret witness at Harris' next parole hearing.
The late Detective Inspector John Hughes, the officer in charge of the case codenamed Operation Stockholm, did go to Harris' parole hearing in support of him but parole was denied.
Hughes was known by those in the criminal world as "the gardener" due to accusations he tampered with or placed evidence in cases.
"The fact of the matter is [Tamihere] never made any confession to me of any kind. [Tamihere] actually always maintained his innocence," Harris wrote in the affidavit.
"By making this affidavit I realise that I may be compromising my own best interests. Violent reaction from other prisoners is likely. Police and prison officers and other official persons maybe equally unforgiving. They may exert pressure on me through their contact within the justice system."
It was on July 17, 1996 that Harris was famously interviewed by the late Sir Paul Holmes - John Tamihere had leaked the affidavit to the press.
Harris affirmed, live on primetime television, that he was retracting his trial evidence and said his testimony was "playing on his mind" and "they definitely have an innocent man inside".
The secret witness, whose voice was altered to protect his identity, told Holmes that police had offered him "major inducements" and were aware it was all a lie.
"There was nothing on paper, it was all verbal, and I took their word for it," Harris said.
"I never got anything."
"He always maintained his innocence to me," Harris said of Tamihere.
"I'm terribly sorry," he added.
However, just a few weeks after the Holmes interview, Harris retracted his affidavit and on August 8, 1996, produced two handwritten statements to police.
He claimed the affidavit was formed under threats from fellow prisoners.
"They would kill me and if they didn't get me, they would butcher my elderly parents. I'm fully aware of how some of these gangs operate, and I took the threats seriously," he wrote in the statement, attached to an Independent Police Conduct Authority report obtained by the Herald.
In another statement, Harris apologised "for bringing into question the integrity and the credibility of the police".
"At the same time I would like it noted it all came about due to a life-threatening sequences of events. That still concerns me and smoulders on my memory with unspeakable anguish," he wrote.
The fear of retribution as a prison nark also led to the phone calls to John Tamihere, Harris said at his perjury trial this year.
Doubt lingers over Tamihere's guilt
A decade passed before Harris, in June 2007, wrote a letter to Tamihere claiming again that the "trial evidence was all false and fabricated by the police anyway".
But, while he wrote the letter he didn't post it, Harris claimed at his perjury trial.
He said he was threatened by the same prisoners who intimidated him in the mid-1990s.
"They were the same ones, they came into my cell wanting me to write this letter," he said.
"'He's a nark and should be killed, what the hell are you doing helping the enemy?'" Harris said other prisoners thought of him.
Tamihere has indicated he will ask the government for a pardon, with Gibson earlier telling the Herald he was working on a prerogative of mercy application under section 406 of the Crimes Act.
The lawyer said it will be a similar argument to the one he made for the late David Dougherty's miscarriage of justice, which led to Dougherty being acquitted at a retrial of the 1993 rape and abduction of an 11-year-old girl.
Gibson indicated he would approach the government for a pardon "in the same way that Arthur Allan Thomas approached [former Prime Minister] Robert Muldoon" in 1979.
Last month, encouraged by his victory over Harris, Taylor targeted another witness in the Tamihere trial - the late Witness B.
He argued for the identity suppression of the second prison informant be revoked.
The Crown opposed the application, but Justice Mark Woolford revoked the suppression order made on November 20, 1990, by trial judge Justice David Tompkins.
It will come into effect from May 1, to allow the Crown to seek further legal options.
The health and whereabouts of Witness A remains unknown.
1989: Paakkonen and Hoglin disappear on the Coromandel Peninsula
1990: Tamihere is convicted of murdering the Swedish travellers
1991: Hoglin's remains are found near Whangamata
1992: The Court of Appeal rejects Tamihere's appeal
1994: Tamihere denied leave to appeal to the Privy Council
1995: Witness C swears an affidavit retracting his evidence
1996: Witness C retracts his retraction
2010: Tamihere is released on parole
2016: A private prosecution alleges Witness C lied at Tamihere's trial
2017: Witness C appeals the perjury convictions and sentence and fights to keep his identity hidden
2018: Witness C drops his appeal against the perjury convictions and is later revealed as Roberto Conchie Harris