David Tamihere is asking the Crown to have another look at jailhouse witnesses after the identity of the person who lied at his 1990 trial for the murder of two Swedish tourists was revealed by the Herald.
Roberto Conchie Harris known before only as "Witness C" was known to Tamihere and was on the same landing as him in prison, Tamihere told Newstalk ZB.
Harris was convicted of perjury for lying at Tamihere's 1990 trial, is also a double murderer and sex offender.
Tamihere was sentenced to life imprisonment in December 1990 for the backpacker murders of Swedish tourists Urban Hoglin, 23, and Heidi Paakkonen, 21.
The prison witnesses all claimed Tamihere had, at different times and while in custody, confessed to how he sexually assaulted and killed the Swedes.
They were known as "Witness A", "Witness B" and "Witness C".
He maintained that all the witnesses had lied and the use of "jailhouse snitches" was a real issue as "they are the most dangerous witnesses you could hope to get in the justice system".
"They can come into a trial and they are not expected to prove what they are saying on the stand.
"They just gotta parrot whatever they are told to parrot," Tamihere said.
He wanted the Crown to have another look at anonymous jailhouse witnesses following his case.
Witness B was to be named next month but he had died in the 90s, Witness A was in Fiji and fighting to keep name suppression, he told Newstalk ZB
The Herald can further reveal that Harris claimed he met Tamihere while Harris was in prison for the double-killing 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 killer. He was later found guilty of their murders by a jury in the High Court at Whangarei.
At Harris' trial, his girlfriend infamously testified that Harris told her that killing the couple was "just like having an ice cream''.
Last year, in a rare private prosecution by "jailhouse lawyer" Arthur Taylor in the High Court at Auckland, Harris was found guilty of lying at Tamihere's trial.
A jury decided he was guilty on eight perjury charges but not guilty of obstructing the course of justice, which pertained to his 1995 affidavit recanting his murder trial testimony.
When sentencing Witness C to eight years and seven months' imprisonment last year, Justice Christian Whata also revoked Harris' name suppression which has stood for nearly 30 years.