The weekly rate of new Covid-19 cases has increased in dozens of areas of England after an Excel spreadsheet error meant almost 16,000 cases went unreported.
The systems failure has also created a delay by the country's NHS Test and Trace to find the contacts of those who tested positive for the virus, in some cases by around a week.
It comes as Britain remains the worst-hit European country, yesterday passing its latest milestone of 500,000 confirmed coronavirus infections.
Meanwhile, British Prime Minister Boris Johnson was unable to say this morning how many contacts of positive cases had been missed.