The Court of Appeal has upheld David Wayne Tamihere's convictions for the 1989 murders of Swedish backpackers Heidi Paakkonen and Urban Höglin.
This is despite finding there had been "a miscarriage of justice" at trial.
In their just-released judgment, the panel of judges concluded false testimony from a jailhouse informant and evidence
about a watch later found to be wrong may have influenced the original jury.
However, the weight of other evidence against Tamihere was enough to establish his guilt "beyond reasonable doubt".
"We accept that it remains impossible to know the couple's precise movements after they were seen in Thames on 7 April
and why they were killed. But we do not accept that it is impossible to prove beyond reasonable doubt that Mr Tamihere
killed them."Timeline of events
7 April 1989 - Heidi Birgitta Paakkonen and Sven Urban Höglin are last seen in Thames.
24 May 1989 - David Tamihere is arrested over an earlier rape. That same day, the couple are reported missing.
5 December 1990 - Tamihere is convicted of murdering the couple and sentenced to life imprisonment.
1991 - Höglin's body is found near Whangamatā.
1992 - The Court of Appeal rejects Tamihere's appeal.
1994 - Tamihere is denied leave to appeal to the Privy Council.
1995 - Witness C - later revealed as Roberto Conchie Harris - swears an affidavit retracting his evidence.
1996 - Harris retracts his retraction.
2010 - Tamihere is released on parole.
2016 - A private prosecution alleges Harris lied at Tamihere's trial.
2017 - Harris is sentenced after being found guilty of perjury and not guilty of perverting the course of justice.
2017 - Harris appeals the perjury convictions and sentence and fights to keep his identity hidden.
2018 - Harris drops his appeal against the perjury convictions.
2018 - The High Court revokes suppression order for Witness B, another prison informant.
2020 - Justice Minister Andrew Little announces Tamihere's case is going back to the Court of Appeal after a royal prerogative of mercy is granted.
November 2023 - The Court of Appeal hears Tamihere's case.
11 July 2024 - The Court of Appeal declines to quash Tamihere's convictions.