It is unacceptable that child services could end up policing their own failings without outside scrutiny, advocates say.
This comes after Child Youth and Family admitted to a list of failings when it sent a toddler back into a P-using household in Southland where he died.
Upcoming law changes that will overhaul CYF, under the new Vulnerable Children Ministry, include requiring that the chief executive set up a complaint mechanism for families.
Under the bill, though, it appears that the only independent scrutiny will be further on down the chain, if a family rejects how their complaint is handled in the first place.
Yet the Minister for Social Development, Anne Tolley, said work had begun on setting up a transparent independent complaints body, in addition to a better complaints process for families.
The Law Society said it was concerned that the handling of complaints might remain within CYF.
Society family law chair Michelle Duggan said: "The recommendation in that bill is that it be a complaints service within the ministry. The New Zealand Law Society, in its submissions on the bill, have said the best sort of complaints service is one that's independent."
The family of the Southland toddler backed calls for outside scrutiny, but also wanted legal teeth added to CYF's safety plans.
The boy's aunt, whose name is suppressed, said her nephew was left alone with the mother's boyfriend in breach of the plan, then found dead the next morning.
"The mother didn't adhere to that plan. She can continue with her life but our nephew is gone because she chose not to adhere to that plan. There's nothing that CYF or the police can do about that.
"There needs to be a change in legislation that allows parties that are part of a safety plan to be held to account - prosecuted."
CYF's own policies say safety plans should be robust and unambiguous and involve the extended family.
The Southland plan was not and did not: social workers set it up with the mother and the boyfriend, as the boy was about to come out of hospital with unexplained injuries.
General manager of family violence group Shine, Jane Drumm, said she would not have been satisfied with that.
"If you've got a situation where there is even the suspicion that one or more parents are going to be neglectful, and they've got responsibility for a child that is highly vulnerable, well, I mean, why on earth would you involve them in the safety plan? That's ridiculous."
CYF did not have enough resources, Michelle Duggan said.
The senior CYF manager who reviewed the Southland case told the extended family that resources were stretched at that time, though she did not want to use that as an excuse for what happened.
"There were capacity issues, there always will be," the manager told the family.
"We know that in that particular week there was real issues within the site... We were really struggling in terms of our staffing levels up to kind of regional headquarters and national office."
Public submissions on the law changes to overhaul Child Youth and Family close this Friday.