(a) Upon the opening of an investigation concerning the alleged abuse or neglect of a child, the Department of Children and Families shall give, when deemed to be in the best interests of the child, notice to the noncustodial parent, custodial parent, guardian of the child and parents if the Department of Children and Families has custody of a child, unless there are reasonable grounds to believe such notice may interfere with a criminal investigation or endanger a person. Such notice shall include (1) the allegation in the complaint, (2) the availability of services from the department, including, but not limited to, child care subsidies and emergency shelter, and (3) the programs of the Office of Victim Services and information on obtaining a restraining order. The notice shall also inform the recipient that such child may be removed from the custody of the custodial parent by the department if such removal is authorized under the general statutes. The department shall employ all reasonable efforts to provide such notice in English or the principal language of the recipient, if known, verbally as soon as practicable after the opening of such investigation or in writing not later than five business days after the opening of such investigation.

(b) Upon a substantiated complaint of abuse or neglect of a child having a single custodial parent or a guardian, the Department of Children and Families shall give, when deemed to be in the best interests of the child, to the noncustodial parent, custodial parent, guardian of the child, and parents if the Department of Children and Families has custody of a child, notice of (1) the circumstances of the complaint, including the name of the person who caused the abuse or neglect, (2) the availability of services from the department, including, but not limited to, child care subsidies and emergency shelter, and (3) the programs of the Office of Victim Services and information on obtaining a restraining order. The notice shall also inform the recipient that such child may be removed from the custody of the custodial parent by the department if such removal is authorized under the general statutes. The department shall employ all reasonable efforts to provide the notice not later than ten days after substantiation of a complaint.

(c) The written notice required under subsections (a) and (b) of this section shall be in English or the principal language of the recipient, if known, and be delivered (1) by certified mail, return receipt requested, directed to the last-known address of each recipient, or (2) by an agent of the department. In the case of personal delivery of written or verbal notice by an agent, written acknowledgment of such delivery shall be made by the recipient.