The board, department and any referee shall have the power to conduct any investigation which may be deemed necessary in any matter properly before them. Such investigations may be made by the board or referee personally, or by any officer or employe of the department, or by any inspector of the department, or by any person or persons authorized by law. Every inspector and employe of the department is hereby empowered and directed to conduct any investigation authorized by this act, at the request of the board, department or any referee, with the consent of the secretary.
77 P.S. § 993