Michigan Compiled Laws, Chapters 760 to 777 Code of Criminal Procedure § 767.4a

Sec. 4a. It shall be unlawful for any person, firm or corporation to possess, use, publish, or make known to any other person any testimony, exhibits or secret proceedings obtained or used in connection with any grand jury inquiry conducted prior to the effective date of this act, except in the manner specifically provided herein, and also excepting any information heretofore disclosed before any investigating committee of the Congress of the United States or any agency of the federal government. Any person violating the provisions of this section shall be guilty of a felony.