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.
( Pub. L. 89–554 , Sept. 6, 1966 , 80 Stat. 545 .)