(215 ILCS 5/153) (from Ch. 73, par. 765)
    Sec. 153. Rebates- Immunity from prosecution.
    No person shall be excused from testifying or from producing any books, papers, contracts, agreements or documents at the trial or hearing of any person or company charged with violating any of the provisions of section 151 on the ground that such testimony or evidence may tend to incriminate himself but no person shall be prosecuted for any act concerning which he shall be compelled so to testify or produce evidence, documentary or otherwise, and no testimony so given or evidence produced shall be received against him upon any criminal investigation or proceeding except for perjury committed in so testifying.
(Source: Laws 1937, p. 696.)