More than 25 years after the Coromandel murders of Swedish tourists Sven Hoglin and Heidi Paakonen, a legal bid gets underway on Wednesday to unmask a secret witness whose evidence helped convict David Tamihere.
The witness is now facing nine charges including perjury and perverting the course of justice.
In the quarter of a century plus since Tamihere was convicted of the murders much has changed, but one thing hasn't - his claim of innocence.
Now secret witness C, a double-murderer himself and one of three inmates who gave evidence against Tamihere, is facing multiple charges of perjury and perverting the course of justice over his decades-old evidence.
It was a testimony that Tamihere, who is on lifelong parole, says sent him down.
"Once they testified, it didn't matter what you said after that."
The witness claimed while they were in jail together Tamihere, who was already a convicted killer and sex offender, confessed he'd dumped the Swedes' bodies at sea, after killing Mr Hoglin with a blow to the head and taking his watch, too.
But almost a year after the trial Mr Hoglin was found buried, with stab wounds and still wearing the watch.
Ms Paakonen's body has never been found.
Over the years witness C has flip flopped, recanting his evidence and then changing his mind back.
There was an appeal and the conviction stood.
Now in a jail house trifecta, the perjury case against the inmate-turned-witness is being brought from behind bars by Arthur Taylor.
He says the prosecution is based on an accumulation of evidence: witness C has since given "secret evidence in other cases" and in 2007 the witness allegedly wrote to Tamihere saying his testimony "was all false and fabricated".
"At the time Jesus Christ himself could have gone to the appeal court and said he didn't do it, and they would have told him to piss off," Tamihere says.
Mr Taylor's private prosecution starts with a bid to lift the name suppression of witness C ahead of the perjury case later this month.
But legal expert Dr Bill Hodge says even without witness C at Tamihere's original trial, there was still a powerful quantity of evidence to support his conviction for the murders.