Federal health officials have expanded a burger recall first announced last week due to possible E.coli contamination.

The Canadian Food Inspection Agency recall initially involved Compliments brand Super 8 Beef Burgers sold in packages of six in Ontario and Atlantic Canada.

The recall now includes Super 6 Beef Burgers sold in packages of 8 in Ontario Sobeys, Sobeys Urban, Foodland, Freshco and Price Chopper stores.

President's Choice Beef Burgers in 4.54-kilogram packages in Loblaws banner stores and Webers Bucket of Burgers sold in 1.02 kilogram packages, also sold nationally, are also being recalled.

The CFIA said Toronto-based Belmont Meats Ltd. was voluntarily recalling the affected burgers and cautions that the recall may be expanded further.

After the initial recall was announced, health officials in southwestern Ontario said lab tests linked three cases of E. coli O157:H7 to the Compliments burgers. The Middlesex-London Health Unit said the three residents of London, Ont., were recovering.

Food contaminated with E. coli O157:H7 may not look or smell spoiled but may cause serious and potentially life-threatening illnesses.

Anyone showing signs or symptoms of E. coli O157:H7 infection, in particular stomach pain and severe or bloody diarrhea, should contact their doctor.