Food safety regulators believe that a General Mills plant in Kansas City is the source of an E. Coli outbreak that sickened dozens of people across 20 states in recent months.
The Food and Drug Administration investigation found that flour produced in the plant during a single week in November 2015 was linked to raw dough eaten or handled by sickened people or used in restaurants.
General Mills last week announced a recall of Gold Medal, Wondra and Signature Kitchens flour produced between Nov. 4 and Dec. 4 over potential links to E. coli O121 illnesses.
The FDA said that the company also notified customers who purchased bulk quantities of those flour brands to make their own products.
E. coli O121 can cause bloody diarrhea and dehydration and can be fatal to those with weakened immune systems. At least 38 people reported E. coli O121 illness between December 21, 2015 and May 3. Ten required hospitalization.
The FDA warned that flour could remain in consumers' homes for long periods of time and continue to pose a danger for E. coli. Regulators urged people to throw the recalled flour away.