The director, for the purposes of this chapter, may issue subpoenas to compel the attendance of witnesses, and/or the production of books and/or documents anywhere in the state. The party shall have opportunity to make his or her defense, and may have such subpoenas issued as he or she desires. Subpoenas shall be served in the same manner as in civil cases in the superior court. Witnesses shall testify under oath which may be administered by the director.