Up to a fifth of patients with coronavirus in several hospitals contracted the disease while being treated as in-patients for another illness, senior doctors and nurses have been informed.
NHS bosses are understood to have shared the information in a national telephone briefing with medics last month, the Guardian reports.
NHS England told the medical directors and chief nurses from all acute hospitals in England that 10pc-20pc of people in hospital with the disease had contracted coronavirus as inpatients during the pandemic.
It's believed that some of the infections were passed on by hospital staff who were unaware they had the virus and had no symptoms, while fellow patients with coronavirus were responsible for the others.