Michigan Compiled Laws, Chapter 600. Revised Judicature Act of 1961 § 600.4706

Sec. 4706.(1) Except as otherwise provided by law, personal property seized under section 4703  1 shall be returned to the owner, or a lien filed against real property under section 4703 or against a motor vehicle under section 4705  2 shall be discharged, within 7 days after the occurrence of any of following:

(2) Before the expiration of period of time prescribed under section (1)(a), the prosecuting attorney, attorney general, or the city or township attorney of the local unit of government where the property is seized or located may petition the court ex parte for not more than an additional 28 days to complete its investigation and issue charges or return the property. The court shall grant an extension under this subsection to the extent necessary upon determining that there is good cause shown for the extension.