A massive number of extra Covid-19 deaths in Germany could indicate 7.9 million Britons have already had the killer bug and survived.
Latest research suggests more than 10 times as many patients in Germany may have been infected with coronavirus than the number of confirmed cases.
The results come after field trials in the worst-hit German towns were conducted by researchers at the University of Bonn, MirrorOnline reports.
The findings serve as a reminder of the dangers of infection by unidentified carriers of the virus, some of whom show no symptoms, the researchers said.
However, the results have yet to be peer reviewed for publication in a scientific journal.
If infection figures in the UK replicated the rate in Germany suggested by the study, it would signal that may millions more people have suffered from the virus without realising it.
Taking into account Britain's official death toll of 29,427 and official infection rate of 194,990, it would mean the case total is as high as 7.9million.
About 1.8 million people living in Germany must have been infected, more than 10 times the number of about 160,000 confirmed cases so far, the team led by medical researchers Hendrik Streeck and Gunther Hartmann concluded.
"The results can help to further improve the models to calculate how the virus spreads. So far the underlying data has been relatively weak," Hartmann said in a statement.
The team analysed blood and nasal swabs from a random sample of 919 people living in a town in the municipality of Heinsberg on the Dutch border, which had among the highest death tolls in Germany.
Researchers analysed the town's number of known deaths compared with a larger estimate of local people with a prior infection - as indicated by antibody blood test readings. The result was then applied to the number of deaths across the country.
About one in five of those infected showed no symptoms.
The University of Bonn readings come as Germany took further steps on Monday to ease restrictions, with museums, hairdressers, churches and more car factories reopening under strict conditions.
