25 U.S. Code § 2715 - Subpoena and deposition authority
By a vote of not less than two members, the Commission shall have the power to require by subpoena the attendance and testimony of witnesses and the production of all books, papers, and documents relating to any matter under consideration or investigation. Witnesses so summoned shall be paid the same fees and mileage that are paid witnesses in the courts of the United States.
The attendance of witnesses and the production of books, papers, and documents, may be required from any place in the United States at any designated place of hearing. The Commission may request the Secretary to request the Attorney General to bring an action to enforce any subpoena under this section.
Any court of the United States within the jurisdiction of which an inquiry is carried on may, in case of contumacy or refusal to obey a subpoena for any reason, issue an order requiring such person to appear before the Commission (and produce books, papers, or documents as so ordered) and give evidence concerning the matter in question and any failure to obey such order of the court may be punished by such court as a contempt thereof.
A Commissioner may order testimony to be taken by deposition in any proceeding or investigation pending before the Commission at any stage of such proceeding or investigation. Such depositions may be taken before any person designated by the Commission and having power to administer oaths. Reasonable notice must first be given to the Commission in writing by the party or his attorney proposing to take such deposition, and, in cases in which a Commissioner proposes to take a deposition, reasonable notice must be given. The notice shall state the name of the witness and the time and place of the taking of his deposition. Any person may be compelled to appear and depose, and to produce books, papers, or documents, in the same manner as witnesses may be compelled to appear and testify and produce like documentary evidence before the Commission, as hereinbefore provided.
Every person deposing as herein provided shall be cautioned and shall be required to swear (or affirm, if he so requests) to testify to the whole truth, and shall be carefully examined. His testimony shall be reduced to writing by the person taking the deposition, or under his direction, and shall, after it has been reduced to writing, be subscribed by the deponent. All depositions shall be promptly filed with the Commission.
Witnesses whose depositions are taken as authorized in this section, and the persons taking the same, shall severally be entitled to the same fees as are paid for like services in the courts of the United States.