The Administration may make such investigations as it deems necessary to determine whether a licensee or any other person has engaged or is about to engage in any acts or practices which constitute or will constitute a violation of any provision of this chapter, or of any rule or regulation under this chapter, or of any order issued under this chapter. The Administration shall permit any person to file with it a statement in writing, under oath or otherwise as the Administration shall determine, as to all the facts and circumstances concerning the matter to be investigated. For the purpose of any investigation, the Administration is empowered to administer oaths and affirmations, subpena witnesses, compel their attendance, take evidence, and require the production of any books, papers, and documents which are relevant to the inquiry. Such attendance of witnesses and the production of any such records may be required from any place in the United States. In case of contumacy by, or refusal to obey a subpena issued to, any person, including a licensee, the Administration may invoke the aid of any court of the United States within the jurisdiction of which such investigation or proceeding is carried on, or where such person resides or carries on business, in requiring the attendance and testimony of witnesses and the production of books, papers, and documents; and such court may issue an order requiring such person to appear before the Administration, there to produce records, if so ordered, or to give testimony touching the matter under investigation. Any failure to obey such order of the court may be punished by such court as a contempt thereof. All process in any such case may be served in the judicial district whereof such person is an inhabitant or wherever he may be found.