(a) In its discretion, the court may order a written investigation and report to assist it in determining any issue relevant to proceedings under this article. The investigation and report may be made by the guardian ad litem, the staff of the court or other professional social service organization experienced in counseling children and families. The court shall specify the scope of the investigation or evaluation and the authority of the investigator.

(b) In preparing the report concerning a child, the investigator may consult any person who may have information about the child and the potential parenting or custodian arrangements. Upon order of the court, the investigator may refer the child to professional personnel for diagnosis. The investigator may consult with and obtain information from medical, psychiatric or other expert persons who have served the child in the past without obtaining the consent of the parent or the child's custodian; but the child's consent must be obtained if the child has reached the age of twelve, unless the court finds that the child lacks mental capacity to consent. If the requirements of subsection (c) of this section are fulfilled, the investigator's report may be received in evidence at the hearing.

(c) The investigator shall deliver the investigator's report to counsel and to any party not represented by counsel at least ten days prior to the hearing unless a shorter time is ordered by the court for good cause shown. The investigator shall make available to counsel and to any party not represented by counsel the investigator's file of underlying data and reports, complete texts of diagnostic reports made to the investigator pursuant to the provisions of subsection (b) of this section, and the names and addresses of all persons whom the investigator has consulted. Any party to the proceeding may call the investigator and any person whom the investigator has consulted for cross-examination. A party may not waive the right of cross-examination prior to the hearing.

(d) Services and tests ordered under this section shall be ordered only if at no cost to the individuals involved, or at a cost that is reasonable in light of the available financial resources.