Updated

Sainsbury's has issued a recall of all of its bagged watercress and salads containing watercress due to an outbreak of E. coli.

The Food Standards Agency (FSA) said 15 people had been taken ill in the outbreak and that Sainsbury's watercress was "one of their lines of inquiry".

"The FSA has made us aware that a small number of people have fallen ill with a bacterial infection, and that one of their lines of investigation is watercress bought at Sainsbury's since August 1," said a supermarket spokesperson.

"Although no traces of contamination has been found in our products we have as a precautionary measure withdrawn six lines of pre-packed salad containing watercress from the supplier concerned."