A senior nurse at Starship hospital's child protection unit told a conference of medical professionals that "all parents are liars until proved otherwise", doctors who attended say.

The revelation comes after a Sunday Star-Times investigation into practices at the unit, Te Puaruruhau, revealed concern it is being run like a police station, with staff treating parents as guilty until proven innocent over unexplained injuries.

Families have complained that the unit's doctors rushed to judgements, refused to budge from their initial assessments, and failed to apologise when injuries were shown to be accidental.

There has also been judicial criticism, with a judge saying doctors in one case seemed to have closed minds and had not considered alternative explanations.

The Auckland District Health Board has told the Star-Times that Starship staff do not assume guilt, and only investigate suspected abuse with good reason and after thorough consultation.

However, the comment, at last year's Goodfellow Symposium at Auckland University, supports the "guilty until proven innocent" complaint.

The presentation by a nurse specialist – "non-accidental injury – patterns and prevention" – was aimed at providing doctors with a synopsis on "the current evidence on the identification and management of non-accidental injuries" in children. The nurse spoke about the need for communication between GPs and hospital staff, and also the need for hospital staff to be "upfront and honest" with families.

But a comment at the start of the speech raised eyebrows.

"She just blankly said the most important thing she'd learnt working in the unit was that all parents are liars until proved otherwise," a GP who attended the session said.

He asked not be named because he did not want to "buy into a fight with Starship" and child abuse was not his area of expertise.

"It's etched in my memory. It gave me a bit of a cold chill.

"How can you communicate, connect or go forward with families if you're starting from that point?

"It's a hell of a turnaround from the way we all normally practise. For by far the overwhelming majority of parents, any thought of harming their children is alien to them.

"I really do feel for those parents who are being dragged through it [an investigation]," the GP said.

A health board spokesman said the board had been unable to get hold of a recording, so could not make a statement on the context in which the comment was made.

The Star-Times has agreed not to name the nurse, given that the full context of her comment cannot be determined, but efforts to get her to expand on what she meant were unsuccessful.

The board said Starship clinicians did not lay charges, or decide guilt.

Specialists might believe there was sufficient clinical evidence to suspect abuse, but from that point other agencies decided on charges, which went before the courts.

"We act to protect the interests of the child while keeping parents informed as investigations unfold."

Former Health and Disability Commissioner Robyn Stent, who spoke out in the Star-Times after her own stepdaughter was wrongly suspected of abusing her baby, was horrified by the "liars" remark.

"This sort of hyperbole suggests phobias and zealotry have taken over and all reason has fled. It justifies the concern the pendulum has swung too far against loving parents. No one wants to expose infants to risk, but the tail must not be allowed to wag the dog," she said.

Stent, who wrote the code of rights for health consumers, said the first right was "respect".

If Te Puaruruhau was required to "act as a forensic arm of the police, then let's be clear about that and separate the unit from everyday Starship care and treatment of children".