James Leota-Tui had gone for a body tattoo traditional among elders of the South Pacific island state despite the pleas of his wife.
The 29-year-old died of necrotising fasciitis in the intensive care unit of an Auckland hospital, three days after abandoning a second session of the long tattooing process.
Police and public health officials are investigating the cause of death and may press charges.
Mr Leota-Tui's wife had threatened to leave him after he underwent a first tattooing session in April which left him with open wounds on his back.
They took so long to heal he was sent home from his job as a tyre retreader.
New law
Despite continuing discomfort from that session, he returned in late June for the second of the three stages of the process.
Necrotising fasciitis
Commonly enters the body through broken skin
Flu-like symptoms and diarrhoea are common symptoms
Sufferers develop toxic shock syndrome as the disease spreads to underlying tissues
May be treated early with antibiotics but amputation may be required at an advanced stage
Seeing her husband's health deteriorate rapidly, Mrs Leota-Tui summoned help but he died in hospital after a 15-hour battle to save his life.
Investigators are now checking samples of tissue from the dead man and the tattoo equipment used for bacteria.
His widow, who is left with a two-year-old son, said he had been about to celebrate his 30th birthday. "James had been looking forward to a big party this month for his 30th," she said.
"Now we're going to have a big funeral instead."
Ironically, Mr Leota-Tui was buried on the same day as a new bylaw came into force in the New Zealand city of Manukau on tattoos and body piercings.
The Health Ministry's director of public health, Dr Colin Tukuitonga, says the link between tattooing and necrotising fasciitis in Mr Leota-Tui has not yet been proven but is most likely.
Mrs Leota-Tui has revealed that a tattooist who had worked on her late husband cleaned his traditional bone tools with Dettol.