(a) The Secretary may issue subpoenas relating to any matter under investigation. A subpoena may:

(1) Require testimony to be taken by interrogatories;

(2) Require the attendance and testimony of witnesses at a specific time and place;

(3) Require access to, examination of, and the right to copy documents; and

(4) Require the production of documents at a specific time and place.

(b) A subpoenaed person may petition the Secretary or the Secretary's designee to modify or withdraw a subpoena by filing the petition within 10 days after service of the subpoena. The petition may be in letter form, but must set forth the facts and law upon which the petition is based.