820 ILCS 175/55
It shall be the duty of the Department to enforce the provisions of this Act when, in the Department's judgment, there is cause and sufficient resources for investigation. The Department shall have the power to conduct investigations in connection with the administration and enforcement of this Act and any investigator with the Department shall be authorized to visit and inspect, at all reasonable times, any places covered by this Act and shall be authorized to inspect, at all reasonable times, contracts for the employment of all day or temporary laborers entered into by a third party client if the Department has received a complaint indicating that the third party client may have contracted with a day and temporary labor service agency that is not registered under this Act. The Department shall conduct hearings in accordance with the Illinois Administrative Procedure Act upon written complaint by an investigator of the Department or any interested person of a violation of the Act. After the hearing, if supported by the evidence, the Department may (i) issue and cause to be served on any party an order to cease and desist from further violation of the Act, (ii) take affirmative or other action as deemed reasonable to eliminate the effect of the violation, (iii) deny, suspend, or revoke any registration under this Act, and (iv) determine the amount of any civil penalty allowed by the Act. The Director of Labor or his or her representative may compel, by subpoena, the attendance and testimony of witnesses and the production of books, payrolls, records, papers, and other evidence in any investigation or hearing and may administer oaths to witnesses. Nothing in this Act applies to labor or employment of a clerical or professional nature.
820 ILCS 175/55