A convicted murderer found guilty of stabbing a triple-murderer in prison has lost an appeal against his conviction.
Dean Joseph Shepherd was caught on a security camera at Paremoremo prison in 2007 attacking William Bell, the man who bashed three people to death at a Returned Services Association premises in 2001.
Shepherd used two metal weapons fashioned from a lever arch file to stab Bell in the eye, before bashing his head.
He is serving a 10-year sentence for wounding with intent to cause grievous bodily harm.
Shepherd last year filed an appeal claiming he attacked Bell in self-defence because he believed that he was in imminent danger of maiming or death.
But the Court of Appeal issued a decision on Monday saying that even if Shepherd was threatened, his reaction was gross and unreasonable and not a defence.