"Police only work with approved agencies such as Victim Support and court victim advisers who help young victims who may be involved in the court process, and would have concerns about any group or individual that has not been appropriately vetted, approved or trained to interact with vulnerable victims, however well-intentioned their motives may be."
The spokesman said police had dedicated, specialist child protection teams and he urged families to approach them first.
A spokesman for Child Youth and Family said the Ministry of Social Development had "no involvement with the group".
Secretary of the Auckland BACA chapter, Anne Murphy, said the organisation's members were not "vigilantes or counsellors".
Their aim was to serve as "an extra layer of protection" for children who feel unsafe or frightened after being victims of abuse.
The group's mission statement was to "empower children to not feel afraid of the world in which they live".
It currently has seven members, including an ex-police officer and social worker. Eight other people are undergoing a six-month training process.
"Children are dying, we want to change that," Murphy, aged 64, told the Herald on Sunday.
"We do not use violence or intimidation. To be a part of the BACA organisation there are levels of training you must complete before you can set up your [chapter], like having a police check. Anyone with a history of abuse, violence or sexual misconduct is turned away immediately."
Services offered include providing escorts for children who feel scared in their neighbourhood, riding by their homes on a regular basis, supporting the children at court and staying with the children if they are alone and frightened.
Members never went to the child's house alone and never without the knowledge or permission of the parents, he said.
Parents can contact the group - which is holding a fundraising ride from Drury, Auckland and then to the Waikato on May 21 - seeking assistance for their children.
"We screen calls and emails because our focus is the children," Murphy said.
"A mother who calls due to fear of violence from a current partner is referred to the police as that is not what we are about.
"Helping these children feel safe and secure is an amazing feeling. We want to take away their worry that someone may return and hurt them again - we are here to help and want to continue to do so for many years to come."