5 U.S.C. § 8126: Subpenas; oaths; examination of witnesses

The Secretary of Labor, on any matter within his jurisdiction under this subchapter, may—(1) issue subpenas for and compel the attendance of witnesses within a radius of 100 miles; (2) administer oaths; (3) examine witnesses; and (4) require the production of books, papers, documents, and other evidence.