(a-5) A representative of the Department or a designated provider agency that is actively involved in an abuse, abandonment, neglect, financial exploitation, or self-neglect investigation under this Act shall be allowed access to the financial records, mental and physical health records, and other relevant evaluative records of the eligible adult which are in the possession of any individual, financial institution, health care provider, mental health provider, educational facility, or other facility if necessary to complete the investigation mandated by this Act. The provider or facility shall provide such records to the representative upon receipt of a written request and certification from the Department or designated provider agency that an investigation is being conducted under this Act and the records are pertinent to the investigation. Any records received by such representative, the confidentiality of which is protected by another law or rule, shall be maintained as confidential, except for such use as may be necessary for any administrative or other legal proceeding.