Public Health England (PHE) said investigations found a possible link to the supermarket’s product that is made in the UK using British beef.
Six cases reported eating the implicated brand and the pathogen has been found in the burgers, it added.
The product was recalled one month after the last illness onset date of 23 November. All patients have made a full recovery.
Whole Genome Sequencing was used to link isolates from cases and product.
The Food Standards Agency (FSA) said it was ‘possible’ that E. coli O157 may be in the burgers.
It would not say if it would or had inspected any parties in relation to the incident but added further investigations are taking place to help determine the origin of the contamination using supply chain information.
"The laboratory test results indicating these burgers to be the likely source were received on 21 December (confirmatory tests are pending) and the recall was published the next day."
Signs of STEC infection
Shiga toxin-producing Escherichia coli (STEC) also known as vero cytotoxin-producing Escherichia coli (VTEC) causes about 800 cases annually in the UK.
VTEC O157 symptoms range from mild to bloody diarrhoea and haemolytic uraemic syndrome (HUS).
Incubation period can be from one to 14 days and is most commonly three to four. Symptoms usually resolve within two weeks.
STEC is destroyed by cooking food until all parts reach a temperature of 70 °C or higher.
Sainsbury’s recalled batches of Taste the Difference 4 pack Aberdeen Angus British Beef Quarter Pounders due to the link to illness.
The supermarket refused to name the supplier but told us it had stepped up controls and was investigating.
TTD Aberdeen Angus Quarter Pounder 454g (frozen) with Best Before End July, September and October 2018 are affected.
Sainsbury's said it knows only those three dates are involved based on information provided by the FSA and investigation with its supplier.
“We've been made aware by the Food Standards Agency of a very small number of customers who may have become unwell with E. coli after consuming this product,” it said.
“As a precautionary measure, we are asking customers who have purchased this product, not to consume it but return it to their nearest Sainsbury’s store, where they will receive a full refund. We apologise for the inconvenience this has caused.”