Stores in nine states have been reported to have received beef contaminated with E. coli O157:H7, the USDA's Food Safety and Inspection Service said.

After the FSIS announced earlier this week that 1.8 million pounds of ground beef products were being recalled due to contamination, five retailers that may have received the tainted products have been confirmed by the federal agency, CNN reported.

They are Gordon Food Service Marketplace stores in Florida, Illinois, Indiana, Kentucky, Michigan, Ohio, Pennsylvania, Tennessee and Wisconsin; Surf N Turf Market in Sebring, Florida; Giorgio's Italian Delicatessen in Stuart, Florida; M Sixty Six General Store in Orleans, Michigan; Buchtel Food Mart in Buchtel, Ohio.

Although the contaminated meat is in the process of being removed from store shelves, consumers should still return or throw out meat that has the code EST.2574B and a production date between March 31 and April 18, 2014, a spokesperson for the U.S. Department of Agriculture said.

According to CNN, the ground beef is sold under a variety of labels, according to the USDA, but comes from Wolverine Packing Company in Detroit.

"While none of the Wolverine Packing product has tested positive for the pathogen implicated in this outbreak, the company felt it was prudent to take this voluntary recall action in response to the illnesses and initial outbreak investigation findings," Chuck Sanger, a spokesman for Wolverine Packing, said in a statement.

The product is suspected to have sickened eleven people across four states, according to the USDA. Ten of those people were sickened after eating at restaurants that received contaminated meat.

However, regulations prohibit federal officials to name those restaurants.

"People who were exposed were already exposed, so it doesn't help the public to tell them now that a certain restaurant was associated with these illnesses," David Goldman, Assistant Administrator for the Office of Public Health Science at the USDA, told CNN. "Our job really is to identify product that may still be available."

The list of stores released Wednesday is not final, a FSIS spokesperson said. As the investigation by the USDA continues, more establishments will be added.