An inquest into the prison death of Antonie Dixon, who killed a man and mutilated two women in a P-fuelled rampage, is set to be held this year after family complaints about a three-year wait for a hearing.
Dixon severed the hand of Renee Gunbie and injured Simonne Butler with a samurai sword before shooting James Te Aute dead on a night of violence in January 2003.
His first convictions were quashed in 2007 by the Court of Appeal but he was again found guilty of eight charges in a retrial the following year.
Prison officials found him dead in his cell from what appeared to be self-inflicted injuries in February 2009, a day before he was due to resentenced.
His sister Carla Dixon told Radio New Zealand the wait for a coroner's inquest into the death was suspicious.