An elderly man died from complications of blood loss after two major blood vessels were damaged, according to an investigation that concluded his surgeon had operated "without reasonable care and skill".
Health and Disability Commissioner Anthony Hill says in a public report that the general surgeon, whose name he has withheld, and the Nelson Marlborough District Health Board breached the code of patients' rights.
He has sent the case to his prosecutor who will decide whether to lay charges against the surgeon at the Health Practitioners Disciplinary Tribunal.
The man, who had had other illnesses, underwent open - as opposed to keyhole - surgery to remove his gallbladder.
The surgeon had told him that it would need to be an open procedure because of a previous surgery.