Eight NHS hospitals in the UK have been hit by the listeria outbreak which has killed five patients, according to an article on the Telegraph website.
Health Secretary Matt Hancock said he wanted see NHS catering be brought back in-house to improve safety.
The outbreak has been linked to pre-packed sandwiches and salads.
Sandwiches and salads linked to the outbreak were withdrawn on May 25, as soon as a link with the cases was suspected. But scientists fear more cases may emerge because listeria has a 70-day incubation period.