Section 29
SEC. 29. All hearing and investigations before the Commission shall be governed by rules adopted by the Commission, and in the conduct thereof the Commission shall not be bound by the technical rules of legal evidence: Provided. That the Public Service Commissioner or Deputy Commissioner may summarily punish for contempt by a fine not exceeding two hundred pesos or by imprisonment not exceeding ten days, or both, any person guilty of misconduct in the presence of the Commissioner or Deputy Commissioner or so near the same as to interrupt the hearing or session or any proceedings before them, including cases in which a person present at a hearing, session, or investigation held by either of the Commissioners refuses to be sworn as a witness or to answer as such when lawfully required to do so. To enforce the provisions of this section, the Commission may, if necessary, request the assistance of the municipal police for the execution of any order made for said purpose.