The US Food and Drug Administration has found that a peanut plant in Georgia identified as the source of the salmonella outbreak shipped out products that may knowingly have been tainted.

Officials at the FDA said in a media call yesterday (27 January) that an inspection of the Peanut Corp. of America (PCA) plant found "at least" two strains of salmonella bacteria, although not the exact strains connected with the current outbreak.

Michael Rogers, director of field investigations for the office of regulatory affairs at the FDA, told reporters: "The team identified approximately 12 instances in 2007 and 2008 where the firm identified some type of salmonella and released the products after they were re-tested."

The FDA also found that after the company had tested the peanut products and found salmonella, it had sent some to an outside lab that showed no contamination. The products were then illegally shipped for sale.

Rogers said there were no steps taken by the company as far as cleaning of manufacturing equipment was concerned or minimising cross-contamination.

Some 501 people in 43 US states and one person in Canada have fallen ill following the salmonella outbreak. Eight deaths have also been linked to the outbreak.

Over 125 products have been recalled, with goods ranging from crackers to ice cream.

PCA has supplied over 70 companies and the likes of food manufacturers General Mills and Ralcorp Holdings and retailers Kroger and Safeway have also recalled products made with ingredients from the firm.

Details of precisely what the FDA found are expected to be released tomorrow.

PCA was unable to be contacted for comment at the time of just-food going to press.