A California man pleaded guilty in federal court to participating in a conspiracy that distributed more than $6.6 million in synthetic marijuana from and to central Missouri businesses.

Federal prosecutors say 40-year-old Michael James Butler, of Sacramento, California, pleaded guilty Tuesday for his role in money-laundering and mail fraud conspiracies. Both conspiracies occurred between December 2012 and July 2015 and were related to the distribution of synthetic marijuana, also known as K2.

Prosecutors say Butler managed a co-conspirator's company that was used to send FedEx packages containing K2 to wholesale customers across the U.S. Butler established another company, Butler-Whayne Industries, which sent K2 packages to locations in Callaway County.

Butler is one of eight people who have pleaded guilty in the case.