225 ILCS 317/75
The Office or hearing officer may compel by subpoena or subpoena duces tecum the attendance and testimony of witnesses and the production of books and papers. All subpoenas issued by the Office or hearing officer may be served as provided for in a civil action. The fees of witnesses for attendance and travel shall be the same as the fees for witnesses before the circuit court and shall be paid by the party at whose request the subpoena is issued. If such subpoena is issued at the request of the Office , the witness fee shall be paid as an administrative expense.
In the case of refusal of a witness to attend or testify or to produce books or papers concerning any matter upon which he or she might be lawfully examined, the circuit court of the county where the hearing is held, upon application of any party to the proceeding, may compel obedience by a proceeding for contempt.
The Office or hearing officer has the authority to administer oaths to witnesses.
225 ILCS 317/75