Any member of the Commission, or any employee of the Commission, designated in writing by the Chairman of the Commission, may administer oaths and examine witnesses. Any member of the Commission may require by subpena the attendance and testimony of witnesses, and the production of all necessary books, papers, documents, records, correspondence, and other evidence, from any place in the United States at any designated place of inquiry or of hearing. The Commission is authorized to contract for the reporting of inquiries or of hearings. Witnesses summoned before the Commission shall be paid the same fees and mileage that are paid witnesses in the courts of the United States. In case of disobedience to a subpena, the aid of any district court of the United States, as constituted by chapter
5 of title
28, and the United States court of any Territory or other place subject to the jurisdiction of the United States may be invoked in requiring the attendance and testimony of witnesses and the production of such books, papers, documents, records, correspondence, and other evidence. Any such court within the jurisdiction of which the inquiry or hearing is carried on may, in case of contumacy or refusal to obey a subpena issued to any person, issue an order requiring such person to appear or to give 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.