35 ILCS 128/1-60
The Department, or any officer or employee designated in writing by the Director thereof, for the purpose of administering and enforcing the provisions of this Act, may hold investigations and hearings concerning any matters covered by this Act, and may examine books, papers, records, or memoranda bearing upon the sale or other disposition of cigarettes or tobacco products by a cigarette machine operator, and may issue subpoenas requiring the attendance of a cigarette machine operator, or any officer or employee of a cigarette machine operator, or any person having knowledge of the facts, and may take testimony and require proof, and may issue subpoenas duces tecum to compel the production of relevant books, papers, records, and memoranda, for the information of the Department.
In the conduct of any investigation or hearing provided for by this Act, neither the Department, nor any officer or employee thereof, shall be bound by the technical rules of evidence, and no informality in the proceedings nor in the manner of taking testimony shall invalidate any rule, order, decision, or regulation made, approved, or confirmed by the Department.
The Director of Revenue, or any duly authorized officer or employee of the Department, shall have the power to administer oaths to such persons required by this Act to give testimony before the Department.
The books, papers, records, and memoranda of the Department, or parts thereof, may be proved in any hearing, investigation or legal proceeding by a reproduced copy thereof under the certificate of the Director of Revenue. Such reproduced copy shall, without further proof, be admitted into evidence before the Department or in any legal proceeding.
35 ILCS 128/1-60