820 ILCS 112/25
The Director of Labor or his or her authorized representative may administer oaths, take or cause to be taken the depositions of witnesses, and require by subpoena the attendance and testimony of witnesses and the production of all books, records, and other evidence relative to the matter under investigation. A subpoena issued under this Section shall be signed and issued by the Director of Labor or his or her authorized representative.
In case of failure of any person to comply with any subpoena lawfully issued under this Section or on the refusal of any witness to produce evidence or to testify to any matter regarding which he or she may be lawfully interrogated, it is the duty of any circuit court, upon application of the Director, or his or her authorized representative, to compel obedience by proceedings for contempt, as in the case of disobedience of the requirements of a subpoena issued by such court or a refusal to testify therein. The Director may certify to official acts.
820 ILCS 112/25