Soleco UK Ltd withdrew watercress products, including own-brand watercress and spinach, and watercress and rocket mixed salad, from sale at branches of Budgens, Co-op, and Florette brand products from a number of convenience stores on January 11 because of possible salmonella contamination.

The affected batches all had use-by dates ranging from 8-13 January and no other batches or products are known to be affected.

The Food Standards Agency was informed immediately and both the agency and Soleco UK have acted promptly to contain the potential problem.

“Salmonella was just found in one bag of watercress in one packing station, but Soleco withdrew all the products containing watercress from that batch,” said an FSA spokesman. “In total that was only about 3,500 bags. This is not a big incident.”

The watercress was grown in Florida and samples of salmonella found are being tested for type and strain by the Health Protection Agency to try and determine the exact source. “This is likely to take a few more days,” said the spokesman on Wednesday.

The batch was withdrawn from sale and described by Soleco as a small potential risk. The company’s managing director Mark Newton told freshinfo: “Our continuous, rigorous quality testing programme identified a small chance of potential contamination in part of this batch. Although the risk was very low, we immediately triggered a withdrawal of the entire batch from retail outlets and the distribution chain. Ensuring the highest quality standards is our number one priority which is why we took this precautionary measure.”

The FSA also said that extensive testing is being carried out by Soleco at the source operations in Florida.