Double murderer John Barlow has had his appeal dismissed by the Privy Council in London.
Barlow was appealing against his convictions for the 1994 murders of father and son Eugene and Gene Thomas in Wellington.
The Privy Council dismissed Barlow's appeal on Monday, meaning the convictions stand, Radio New Zealand correspondent Olly Barratt reports.
The court's judgment did include the proviso there had been a miscarrige of justice in Barlow's case regarding some evidence, but that "no substantial miscarriage of justice actually occurred."
The Privy Council, therefore, considered Barlow, 63, to be guilty of the crimes for which he was convicted.
Barlow twice went through trials that ended in hung juries, before finally being jailed for the murders in 1995. He is serving a 14-year sentence in Rimutaka Prison near Wellington.
In August 1996, the Court of Appeal dismissed an appeal by Barlow.
His legal team brought an appeal to the Privy Council, contending that evidence linking the weapon and bullets that killed the Wellington businessmen to Barlow was flawed.
But Monday's judgment, coming months after the appeal hearing began, sees Barlow's appeal to the highest court in the Commonwealth thrown out.