The grieving mother of a 4-month-old baby who died of respiratory failure was seperated from her partner and questioned by police for almost four hours on the day the baby died.
Melanie Harding and her partner Nick Drever have lodged a complaint with the independent police watchdog over how they were treated after the tragedy.
The heartbroken parents found son Riley Drever dead in their bed two years ago on Monday - and say they were treated like criminals.
And the pathologist who carried out the autopsy has criticised police over a lack of critical detail provided in a briefing report.
Inquiries from the Weekend Herald have prompted police to say they will now contact the family to discuss their concerns.
"They kept asking the same question over and over again in different form. 'Did you do something to Riley?'," Harding said.
"The more desperately I was trying to explain to them, Riley was sick, Riley had been to the doctor so many times, the more they would say, 'What was your mental state like, how much did you sleep, did you have any drugs, how did Sophie move him?'.
"I'd just lost my baby."
The grieving mother was questioned for four hours at the Hamilton Central Police Station while partner Nick Drever waited outside, before being presented with a "suspicion of manslaughter" search warrant.
The family were not allowed back in their home until police collected evidence. They took Riley's baby blankets, sheets, a bottle and Well Child book.
An autopsy showed Riley died of respiratory failure and bronchopneumonia, secondary to congenital laryngomalacia - a birth defect which caused a severe stridor (high-pitched breath) and continuous breathing difficulties.
Harding, 25, had taken her son to doctors 16 times in the months before his death and he was admitted briefly to Waikato Hospital.
His care is now the subject of a Health and Disability Commission investigation.
The pathologist who performed Riley's autopsy told Harding: "It wasn't your fault, and he wasn't in pain".
In her report pathologist Deborah Johnson said the autopsy was hindered by a lack of information about the pre-existing condition laryngomalacia, when the cartilage in the voice box is floppy, which 90 per cent of children grow out of by age two.
She said police knew about the condition but did not report it to her.
"The emphasis instead was on the perceived unsafe sleeping situation they believed was likely responsible for the death and charges that might possibly be brought for neglect."
On the morning Riley died the baby was moved from his bassinet by older sister Sophie, then aged 2 1/2, to their parents' bed.
Police cordoned off the bedroom and Harding was interviewed at length. Drever had been at work when Riley was discovered.
Police wanted to put paper bags over Riley's head and hands to preserve evidence but Harding's mother, a nurse, refused.
Cariena Harding, 23, said the police inquiry was so intense she began to question whether her sister was capable of hurting Riley.
"Because of the way they handled everything, I believed that my sister had actually done something," she said
"And I've known her my whole life. She would risk her own life to save a hedgehog off the street."
A family statement to the Coroner including a complaint about police insensitivity was sent by Harding to the Police Commissioner about five months after Riley's death, but a police spokeswoman said they had no record of a complaint of police service.
Harding lodged a formal complaint to the Independent Police Conduct Authority yesterday.
She wants an apology and for processes to change "so this never happens again".
A police spokeswoman said the case remained with the Coroner but police would contact the family.
"Police are unable to substantiate that we acknowledged failings in the way the family were dealt with however police staff will make contact with the family to discuss their concerns."
In sudden deaths police work with medical professionals and speak to witnesses and family to help the coroner understand the cause of death, to reduce chances of other deaths in similar circumstances.
"When a person dies suddenly this can be a shock and an emotional time for those known to the deceased," the spokeswoman said.
"Police work hard to be empathetic in these situations and are aware that the investigation process can be hard for those involved, however it is important the information is gathered to allow the coroner to understand the circumstances and cause surrounding the death."