(Newser) – The mystery of the man who appeared to be contaminating food at a Michigan Whole Foods has apparently been solved. It was a tip from the public that the FBI says led to the arrest of the unidentified man, who has copped to pouring a mouse poison concoction on food at the Ann Arbor Whole Foods and other stores over the last two weeks, the Detroit News reports. "The suspect has admitted to using a potentially hazardous material to contaminate food in several Ann Arbor-area grocery stores," says the FBI special agent who heads up the agency's Detroit office. "Our joint investigation leads us to believe that this individual sprayed a liquid mixture of hand sanitizer, water, and Tomcat mice poison on produce."

CBS Detroit names more than a dozen other stores that may have been affected, including other Whole Foods locations, several Meijer and Walmart stores, and a Target, and notes samples from those stores are being tested. "[We] encourage consumers to dispose of any foods purchased from salad bars, olive bars, and ready-to-eat hot and cold food areas from these stores between mid-March and the end of April," says a state official. Still, authorities from the state's Department of Agriculture and Rural Development say they don't expect to receive any illness reports regarding any affected food at this point; the chemicals involved are said to be similar to those found in anti-clotting medications. (Maybe send the suspect to the South Farallon Islands?) Authorities haven't speculated on a motive. (Read more Whole Foods stories.)

