Michael Murray, who murdered Head Hunters gang member Connor Morris three years ago in a street fight, has lost his appeal against his conviction.
Morris, who was the partner of Millie Elder-Holmes, died instantly when Murray hit him in the back of the head with a sickle, piercing his skull, during a fight in West Auckland on August 3, 2014.
His defence argued against a murder conviction, arguing Murray had been defending his brother when he killed Morris.
But in September 2015 Murray was found guilty of murdering Morris and jailed for life with a minimum non-parole period of 10 years.
Murray appealed the conviction, his lawyer arguing that media interest in Morris' death led to an unfair trial because his partner Elder-Holmes was the daughter of the late broadcaster Paul Holmes.
More than 270 stories about Morris' death were published in the media in the year leading up to the trial, many sympathetic towards Elder-Holmes.
Murray's lawyer also said the jury was at risk of being intimidated into convicting Murray by the involvement of the Head Hunters. Large numbers of gang members attended court during the trial.
The appeal against Murray's conviction was heard in the Court of Appeal in Wellington in July.
Justices Rhys Harrison, Denis Clifford, and Brendan Brown released their decision on Thursday, dismissing the appeal.
They rejected claims that the widespread media coverage would have swayed the jury either for or against Murray, saying Justice Wylie clearly put precautions in place to avoid bias on the part of the jury.
The justices considered that although the public would have a degree of "morbid curiosity" in such events, it would not necessarily translate to such a degree of sympathy for Elder-Holmes that it would prejudice Murray's right to a fair trial.
They also dismissed the defence's argument that the jury would have been unduly intimidated by gang members or fears of retribution. Claims that the judge had misdirected the jury over the details of self-defence were also rejected.
Murray is serving a life sentence for Morris' murder. He must spend 10 years in prison before he is eligible for parole.