Starship hospital child protection team leader Dr Patrick Kelly says he feels "blindsided" by major changes proposed in the white paper on vulnerable children.
He says proposals to use a "predictive risk model" to help select 20,000 to 30,000 vulnerable children for a new shared national database risk upsetting years of work towards more informal inter-agency collaboration in child abuse cases.
"I'm all for better collaboration - that's what I've been trying to work for for 20 years - but I guess I thought that could be achieved by evolution rather than revolution," he told the Weekend Herald.
Dr Kelly was part of an eight-member expert forum in 2009 which sketched the first outline of a plan to tackle the high child abuse rate.
But he said he was not kept informed of the white paper's development and felt both the new predictive risk model and a proposed new "Child Protect" call centre, outside Child, Youth and Family (CYF), came "out of left field".