Board authorized to take testimony and issue subpoenas.

Any member of the Board shall have power to administer oaths and the Board may require by subpoena the attendance and testimony of witnesses, the production of all books, registers, and other evidence relative to any matters under investigation, at any public hearing, or at any session or any conference held by the Board. In case of disobedience to a subpoena the Board may invoke the Superior Court of the District of Columbia in requiring the attendance and testimony of witnesses and the production of documentary evidence. In the case of contumacy or refusal to obey a subpoena, the Court may issue an order requiring appearance before the Board, the production of documentary evidence and the giving of evidence touching the matter in question, and any failure to obey such order of the Court may be punished by such Court as a contempt thereof.