225 ILCS 225/14
The Director or Hearing Officer may compel by subpoena or subpoena duces tecum the attendance and testimony of witnesses and the production of books and papers and administer oaths to witnesses. All subpoenas issued by the Director 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 to such proceeding at whose request the subpoena is issued. If such subpoena is issued at the request of the Department, the witness fee shall be paid as an administrative expense.
In cases of refusal of a witness to attend or testify, or to produce books or papers, concerning any matter upon which he 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 proceeding as for contempt.
225 ILCS 225/14