Convicted murderer David Tamihere says he's "real dirty" on secret witnesses after the name was revealed today of one who helped convict him of the murders of two Swedish tourists in 1989.
Robert Conchie Harris has been known simply as 'Witness C' for nearly 30 years, his identity a secret, and last September the jailhouse 'snitch' was convicted of perjury for giving false evidence in the Tamihere case.
Harris's explosive evidence played a major part in convincing a jury that David Tamihere was the man who killed Swedish tourists Heidi Paakkonen and Urban Hoglin on the Coromandel Peninsula. But his testimony was found to be all lies.
"I've got a real dirty on these secret witnesses. You've got no idea to see how dirty I am on them," Tamihere told 1 NEWS.
"I reckon it's high time that this cellmate confession stuff gets stopped," he added.
1 NEWS can now reveal Harris is a career criminal - a double murderer who executed a couple on a remote Northland property in 1983.
Secret witness researcher Mike Kalaugher said Harris "left both their bodies lying on the ground after he had shot them so that their children would find them on their way home from school".
Harris has been twice released on parole and twice recalled back to prison, most recently for a sexual offence.
And thanks to the private prosecution of another inmate, Arthur Taylor, 69-year-old Harris is now serving another eight years for perjury.
It's just completely misleading for jurors- Mike Kalaugher, secret witness researcher
"This is a serial liar," said Richard Francois, Arthur Taylor's lawyer.
Harris claimed Tamihere told him he'd brutally murdered the Swedish couple, but twice retracted that, once on national television.
Witness C, was asked on the Holmes programme in July 1996: "Did he ever say anything to you like, 'I killed the Swedes?'"
Witness C replied: "No, he always maintained his innocence to me."
Mr Kalaugher said today: "This is the criminal who's going to tell the truth about what really happened. That's the way it's portrayed. And it's just not true. It's just completely misleading for jurors."
Mr Francois said: "He's been used by the police time and time again, and they know it."
In some countries jailhouse witnesses are banned. In Canada their credibility is first tested by an independent panel of prosecutors. In New Zealand there are no plans to change the way we use prison informants.
David Tamihere was released on parole in 2010. He could be recalled to prison at any time.
He's hoping the Government's plans to establish a Criminal Cases Review Commission will one day clear him of the Swedish murders.