452.390.  Investigation and report on custodial arrangements for a child — how conducted — report due, when — material to be available to counsel and parties. — 1.  The court may order an investigation and report concerning custodial arrangements for the child.  The investigation and report may be made by the county welfare office, the county juvenile officer, or any other competent person.

  2.  In preparing his report concerning a child, the investigator may consult any person who may have information about the child and his potential custodial 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 he has reached the age of sixteen, unless the court finds that he lacks mental capacity to consent.

  3.  At least ten days prior to the hearing the investigator shall furnish his report to counsel and to any party not represented by counsel.  No one else, including the court, shall be entitled thereto prior to the hearing.  The investigator shall make available to counsel and to any party not represented by counsel an investigator's file of underlying data and reports, complete texts of diagnostic reports made to the investigator pursuant to the provisions of subsection 2, and the names and addresses of all persons whom the investigator has consulted.  Any party to the proceeding may call as witnesses the investigator and any person whom the investigator has consulted.