Two more hospital patients have died after eating pre-packaged sandwiches and salads linked to an outbreak of listeria.
It takes the number of deaths to five, among nine cases in all of the bacteria infecting patients, Public Health England (PHE) said.
The source of the infection is understood to relate to products supplied by The Good Food Chain and the affected ones have since been removed from hospitals.
PHE said evidence suggests all of those who died consumed the products before the withdrawal happened on 25 May.
The first three confirmed victims were at Manchester University NHS Foundation Trust and Aintree University Hospital NHS Foundation Trust in Liverpool.
It is not yet known where the latest two victims were receiving treatment, but PHE said there are seven trusts across the country dealing with listeria cases.
One is believed to have died after the first three confirmed cases, while the other died before.
The first case showed symptoms on 25 April and sandwiches and salads were withdrawn on 25 May.
It is understood that some of the products were sold at hospitals while others were given to patients.
The supplier, The Good Food Chain, meat producer North Country Cooked Meats and distributor North Country Quality Foods have voluntarily ceased production during the investigation.
PHE said: “Whilst any risk to the public remains low, PHE’s Whole Genome Sequencing analysis has identified an additional three cases of listeria linked to this outbreak.
“This brings the total number of confirmed cases to nine. All of the cases of listeria infection were in hospital patients in England.
“Sadly, one of the seriously ill six patients PHE confirmed last week has since died.
“One of the patients confirmed today as linked to the outbreak had already died. This brings the number of deaths linked to this outbreak to five.”
Dr Nick Phin, deputy director at the national infection service at PHE, said: “To date, there have been no patients linked to this incident outside healthcare organisations, but we continue to investigate.
The Good Food Chain said: “Our thoughts and deepest sympathies are with the families of those who have died and anyone else who has been affected by this outbreak. The underlying cause of it remains unclear.
“For our part, we are co-operating fully and transparently with the FSA (Food Standards Agency) and other authorities, and will continue to do so”.
Listeria bacteria can cause listeriosis – a form of food poisoning – and can be found in unpasteurised milk and chilled foods, such as pate, certain cheeses, cold meats and smoked salmon.
It is usually not dangerous for healthy individuals, but can cause vomiting and diarrhoea.
But for people with pre-existing health conditions and weaker immune systems, the infection can prove more serious.
It is most likely to be found in pregnant women, young babies and the elderly.