Dramatic scenes occurred in the Auckland District Court on Tuesday morning when a woman broke down in tears as an inquest into the mysterious death of her mother began.
Heather Bills had to be rescued by neighbours following a house fire on the November 24, 2012, before she was taken to Middlemore Hospital.
Chief coroner Deborah Marshall told the court Ms Bills' condition was improving in hospital and she was expected to recover - that was until she deteriorated suddenly and unexpectedly at about midnight on December 26, 2012.
A call was made to the Intensive Care Unit during which a doctor asked for Ms Bills' blood sugar level and was told that it was "normal", therefore believed he was treating her for a respiratory disorder.
At 2.52am, another blood test was taken from Ms Bills which resulted in a blood glucose level reading of 0.1. The court was told "this was not noticed by the attending medical staff".
At 4.30am, a doctor reviewed Ms Bills' medical notes and realised her blood sugar levels were "extremely low". An intensive glucose treatment by infusion was commenced.
Bills remained in the Intensive Care Unit for the next six days but died on January 2, 2013.
A police investigation was then launched to "determine any criminal liability" in relation to the death.
Today, Detective Senior Sergeant Ross Ellwood told the court, "there was a clear suspicion that she had been injected with insulin".
Det Snr Sgt Ellwood says Ms Bills' "hypoglycaemia" seems likely to have started around 10:30pm - 11:30pm on December 26 and continued until glucose infusion was started about 04:30am on December 27, and that prolonged and profound hypoglycaemia seems most likely to have resulted from a large dose of insulin.
Mr Ellwood said the insulin "would have to be administered by injection, which is usually drawn up into a syringe in hospital but usually dispensed from an 'insulin pen' in the community".
"We understand that Ms Bills was unable to leave her bed, so it would be necessary for someone to bring insulin in a syringe or pen to the bed. It is not clear whether she would have physical capability to inject herself."
Ms Bills was not a diabetic.
This morning, Ms Bills' daugher Michelle Maher broke down in court while speaking about her mother's death.
She said almost five years later, the family desperately want answers.
Ms Maher said her mother was a teacher, small business owner and a great cook.
"Tragically, my children will never get to know their nana," Ms Maher told the court.