The sandwich maker Greencore, which supplies big supermarkets including Asda, Morrisons and Sainsbury’s, is one of a number of companies recalling products after being potentially linked to an UK outbreak of E coli that has now doubled to more than 200 cases.

The company is recalling thousands of sandwiches, wraps and salads sold through those three supermarkets and also Boots, Aldi, Amazon and the Co-op, which contain a certain variety of salad leaf linked to the outbreak identified this month by the UK Health Security Agency (UKHSA).

The recall covers 45 different products, including Asda’s chicken and bacon club sandwich, Boots’s BLT, Asda tuna crunch sub roll and Sainsbury’s peri peri chicken wrap.

The other manufacturers expected to issue recalls have yet to be identified as investigations are continuing into exactly which products have been affected.

Sources said the items being recalled were not believed to contain E coli, as the batch of leaves affected has now been used up, but customers and retailers are being asked to return the items as a precaution.

The Food Standards Agency (FSA) said sandwich manufacturers were taking “a precautionary measure” to recall various sandwiches wraps and salads in response to findings from investigations into the “ongoing outbreak” of shiga toxin-producing E coli (Stec).

More than 100 people across the UK have fallen ill and dozens have been hospitalised with food poisoning in the outbreak so far.

Darren Whitby, head of incidents at the FSA, said: “This is a complex investigation, and we have worked swiftly with the relevant businesses and the local authorities concerned to narrow down the wide range of foods consumed to a small number of salad leaf products that have been used in sandwiches and wraps. Following thorough food chain analysis, these products are being recalled as a precaution.

“Infections caused by Stec bacteria can cause severe bloody diarrhoea and, in some cases, more serious complications. We therefore advise any consumers who have any of these products not to eat them.

Andrew Opie, the director of food and sustainability at the British Retail Consortium, said: “Food safety is the highest priority for our members and those who sell or prepare food are well-versed in food safety measures.

“Retailers affected are taking swift action to remove these products from sale and are working closely with the Food Standards Agency to take any further action needed to minimise risk to their customers.”

Earlier this month, UKHSA said 113 recent UK cases of E coli since 25 May were thought to be part of a single outbreak, which is most likely linked to a “nationally distributed food item or multiple food items” owing to the wide geographic spread of cases, the agency said.

At that time there had been 81 cases in England, 37 of whom admitted to hospital as a result, 18 in Wales, 13 in Scotland, and one person in Northern Ireland who believes they contracted the illness in England. It is understood the total number of cases has now risen.

The cases were described as being part of a single outbreak, most likely linked to a “nationally distributed food item or multiple food items” because of the wide geographic spread of cases, according to the UKHSA.

Of the 81 cases in England, 61 provided the UKHSA with information regarding food, travel and potential exposures. All of the cases have been linked to Stec.

Supermarkets are issuing notices asking shoppers who have bought any of the affected products, not to eat them but bring them back to a store where they will be given a full refund.

Greencore said in a statement: “As a precautionary measure, we have voluntarily recalled a number of sandwiches and wraps due to a potential food safety risk.

“Greencore adheres to the highest standards of food safety, and we are working closely with the Food Standards Agency and our suppliers to better understand the possible source of any potential issue.”