Duffy Smith of Belmont Meats said the Canadian Food Inspection Agency is checking where the beef trim that his company uses to make burgers came from so that the source of the E. coli can be traced.
"We fully vetted all our production systems and checks. They cover the gamut of federal requirements for handling raw meat and our operations are clean," Duffy said Wednesday.
"They (CFIA) have gone back into the supply chain and they are working with several suppliers trying to source where the contamination came from."
Guy Gravelle, a spokesman for the CFIA, said in an email from Ottawa that he could confirm that the agency continues to investigate.
Last Thursday, the Ontario Ministry of Health said that some of the recalled beef has been linked to nine confirmed cases of people getting sick from E. coli in the province, two probable cases and four suspected cases.
Smith said the beef Belmont uses is certified and inspected by the CFIA from Canadian beef suppliers, which he declined to name.
The three main beef-processing plants in the country include two operated by Cargill Canada in High River, Alta., and Guelph, Ont.
The other is the JBS Food Canada Inc. plant in Brooks, Alta., formerly owned by XL Foods. The plant was at the centre of the largest meat recall in Canadian history last year. Eighteen people became ill.
Cargill spokeswoman Brigitte Burgoyne said the company is following the investigation closely.
"Early in the investigation CFIA inquired at High River about a very limited amount of product and reviewed our processes using the CFIA protocols, as they do in all cases such as this one," she said from Winnipeg.
"We provided them with the information requested. There were no inquiries to our Guelph facility."
She declined further comment and referred all other questions to the CFIA.
JBS Canada officials were not available for comment.
Since the agency began issuing health hazard alerts earlier this month about possible E. coli, Belmont has recalled about 68,000 kilograms of beef, including products distributed across Canada.
The CFIA warns that food contaminated with E. coli O157:H7 may not look or smell bad, but eating it may cause serious and potentially life-threatening illnesses.
Details of the alerts and recalls, including which products are involved, are posted on the agency's website.
— By John Cotter in Edmonton