The Secretary may issue subpenas requiring the attendance and testimony of witnesses or the production of any evidence in connection with such investigations. The Secretary may administer oaths, examine witnesses, and receive evidence. For the purpose of any hearing or investigation provided for in this chapter, the authority contained in sections
49 and
50 of title
15, relating to the attendance of witnesses and the production of books, papers, and documents, shall be available to the Secretary. The Secretary shall conduct investigations in a manner which protects the confidentiality of any complainant or other party who provides information to the Secretary in good faith.