Whenever the Commission has reason to believe that any person may be in possession, custody, or control of any documentary material or tangible things, or may have any information, relevant to unfair or deceptive acts or practices in or affecting commerce (within the meaning of
section 45(a)(1) of this title), or to antitrust violations, the Commission may, before the institution of any proceedings under this subchapter, issue in writing, and cause to be served upon such person, a civil investigative demand requiring such person to produce such documentary material for inspection and copying or reproduction, to submit such tangible things, to file written reports or answers to questions, to give oral testimony concerning documentary material or other information, or to furnish any combination of such material, answers, or testimony.