The department may examine any books, papers, or memoranda bearing upon the determination of the ability to support and for this purpose may, by means of subpoenas issued by its commissioner or his duly authorized representative, compel the attendance of witnesses and the production of relevant documents. Subpoenas of witnesses shall be served in the same manner as if issued by a superior court. If any person fails to obey a subpoena issued and served under this Code section with respect to any matter germane to the department’s investigation, on application of the department, through the commissioner of human services or his duly authorized representative, the superior court of the county in which the person was required to appear may issue an order requiring the person to comply with the subpoena and to testify and to produce the relevant documents.