Upon receipt of a request for hearing as provided in § 44.14 of this part, the Administrator shall, within 5 days, refer to the Chief Administrative Law Judge the original petition, the proposed decision and order, all information upon which the proposed decision was based, any written request for a hearing on the petition filed, any other written comments or information received and considered in making the proposed decision. The MSHA investigation report shall be made part of the record on the petition.