((a)) ** .—** The Secretary may conduct investigations and inspections regarding compliance with this chapter and regulations prescribed under this chapter.

((b))

((1)) ** .—** For the purposes of any investigation conducted under this section, the Secretary may issue a subpoena to require the attendance of a witness or the production of documents or other evidence relevant to the matter under investigation if—

((A)) before the issuance of the subpoena, the Secretary requests a determination by the Attorney General as to whether the subpoena—

((i)) is reasonable; and

((ii)) will interfere with a criminal investigation; and

((B)) the Attorney General—

((i)) determines that the subpoena is reasonable and will not interfere with a criminal investigation; or

((ii)) fails to make a determination with respect to the subpoena before the date that is 30 days after the date on which the Secretary makes a request under subparagraph (A) with respect to the subpoena.

((2)) ** .—** In the case of a refusal to obey a subpoena issued to any person under this section, the Secretary may invoke the aid of the appropriate district court of the United States to compel compliance.