A few weeks ago the Clay County Sheriff's Department began investigating why several people who were vendors at the Covered Bridge Festival became ill.
All of those involved ate at a carry in for vendors near SR59 and Hendricks Street north of Brazil.
Police say that now this has turned into a criminal investigation since lab tests of the food served show the presence of a substance used to manufacture synthetic marijuana.
Several of those that became ill required treatment at a nearby hospital after eating a pan of cornbread.
Clay County Sheriff’s officials say that the people that made the cornbread admitted to them to using the same pan in the past to make synthetic marijuana.
Police are continuing their investigation.