Mich. Comp. Laws § 49.158
No prosecuting attorney shall receive any fee or reward from or on behalf of any prosecutor or other individual for services in any prosecution or business to which it shall be his official duty to attend, nor be concerned as attorney or counsel for either party other than the state or county in any civil action depending upon the same state of facts upon which any criminal prosecution commenced or prosecuted shall depend, or in any action for malicious prosecution brought in consequence of any criminal prosecution commenced or prosecuted during his term of office in the county of which he is prosecuting attorney; nor shall any attorney be permitted to prosecute or aid in prosecuting any person for an alleged criminal offense where he is engaged or interested in any civil suit or proceeding depending upon the same state of facts against such person directly or indirectly.
MCL 49.158