Butcher's Choice Hickory Barbecue Beef Burgers are included in the recall. (CFIA)

Federal officials are investigating five cases of E. coli-related illness in connection with a nationwide beef burger recall.

Authorities say the illnesses were in Ontario and Alberta, and the people involved are recovering. The consumption of frozen burgers was a common thread among the cases

The Canadian Food Inspection Agency (CFIA) is warning the public not to consume certain Butcher's Choice Beef Burgers.

The recall has been further expanded to include all best-before dates. Previously, the recall only included products with best-before dates of Feb. 1, Feb. 10 and March 3.

The affected products, sold in 1.1.3 kilogram packages, are:

  • Butcher's Choice Hickory Barbecue Beef Burgers (UPC code 0 60383 89364 4).
  • Butcher's Choice Garlic Peppercorn Beef Burgers (UPC code 0 60383 89363 7).

Loblaw Companies Ltd. is recalling the product as a precautionary measure.

The CFIA says it is testing additional products collected from across the country and is conducting an investigation involving Cardinal Meat Specialists in Brampton, Ont.

The agency says its inspectors have examined the plant and believe it has been handling food appropriately.

Officials are now tracing back the beef and spices used by the plant to see if the contamination was brought in with the raw ingredients.

If so, they say more food recalls could be coming.

Food contaminated with E. coli can cause serious and even life-threatening illnesses. 

Symptoms include severe abdominal pain and bloody diarrhea, while others may have seizures or strokes and some may need blood transfusions and kidney dialysis. In severe cases of illness, people may die.

With files from CBC News