225 ILCS 135/115
The Department may subpoena and bring before it any person in this State and take the oral or written testimony or compel the production of any books, papers, records, or any other documents that the Secretary or the Secretary's designee deems relevant or material to any investigation or hearing conducted by the Department with the same fees and mileage and in the same manner as prescribed in civil cases in the courts of this State. The Secretary, the shorthand court reporter, and the designated hearing officer may administer oaths at any hearing which the Department conducts. Notwithstanding any other statute or Department rule to the contrary, all requests for testimony and for the production of documents or records shall be in accordance with this Act.
225 ILCS 135/115