The Director, claims adjudicator, or other representative of the Director and any Referee and the Board of Review, or any member thereof, shall have the power, in the discharge of the duties imposed by this Act, to administer oaths and affirmations, certify to all official acts, and issue subpoenas to compel the attendance and testimony of witnesses, and the production of papers, books, accounts and documents deemed necessary as evidence in connection with a disputed claim or the administration of this Act.