A complaint has been made to the Health and Disability Commissioner over the five-month-old Nelson girl diagnosed on the day she died as having "the worst survivable profound brain dysfunction".

Commissioner Ron Paterson said yesterday that he had received a complaint but an investigation had not started.

The complaint is understood to have been made by a member of the baby's extended family.

Mr Paterson said formalities prevented him revealing any details, including whether the complaint related to the care of the child - known as Baby C - or the way the parents were given the diagnosis.

It took only 47 minutes on Thursday for an eight-woman, four-man jury to find the baby's father not guilty of murder or manslaughter, despite his admission during the trial that he held his hand over the baby's face until she stopped breathing.

After the verdict in the High Court at Nelson, the acquitted man's father-in-law said his family went through six months of "living hell" before the murder trial.

"It's been like a dream you can't wake up from," NZPA quoted him as saying.

"We knew all along he wasn't guilty. The verdict is an indication of what we know, of our feelings.

"We can now grieve for her properly. We haven't been able to do that. We have always had this thing hanging over us. I wouldn't wish it on anybody."

The family could now take plans for a family wedding in January "off hold", the father-in-law said.

During the trial the defence case focused on the stress and anxiety the parents faced as they waited to find out what was wrong with their daughter.

It took almost two months to get an appointment for a scan at Christchurch Hospital that would provide the final diagnosis, but even then they had to wait another day to find out what it meant.

The court was told that neurosurgeon Martin MacFarlane showed the parents the scan results in a nurses' station, which was in a public part of the hospital ward.

The scan showed their baby's brain was "in bits and pieces", the baby's mother would later say.

The nurse assigned to the family while they were at Christchurch Hospital, Amanda Jones, would later apologise to them for having to receive such devastating news in such a public way.

And at a pre-trial hearing, she agreed with defence lawyer Greg King that it was "not the most sensitive environment" in which to view such scans.

But she said the nurses' station was one of the few places in the ward with connections for the laptop computer Mr MacFarlane used to show the family the scans.

In part of Mr McFarlane's statement read to the jury during the trial, he said he "was aware that the news I was about to give would indicate there was no surgical solution and would have implications for her ongoing development".

The next day the couple saw paediatric neurologist Paul Shillito, who explained the rare disorder - lissencephaly - in more detail, telling them their baby's brain was as developed as that of a 13-week-old foetus and would never improve.

She would be "severely physically and intellectually disabled and would need adult support for all of her daily activities for the rest of her life. She would have to be fed and changed regularly by someone."

In his statement to the court, Mr Shillito said that had the couple lived in Christchurch, they would have seen a hospital social worker, their GP would have been notified and they would have returned to the hospital in a week where "I would have had further discussions with them".

"As they were returning to Nelson, procedures were put in place for the Nelson paediatric department to provide this follow-up."

After the consultation Ms Jones walked the couple to the door and gave them a taxi chit to get them back to where they were staying.

Mr Shillito said he knew of five other cases of lissencephaly in New Zealand at that time.

Yesterday, Canterbury District Health Board chief executive Jean O'Callaghan said Christchurch Hospital would co-operate fully with the commissioner "to resolve any concerns as soon as possible".

On National Radio yesterday, the board's chief of medicine, Kelvin Lynn, said that "what happened with the care of the child and the information given" would be investigated.

"We can learn from things like that."