Britain saw a record number of single-day coronavirus cases yesterday, with more than 12,000 new infections.
The Government said that, as of 9am on Saturday, there had been a further 12,872 lab-confirmed cases of the disease - nearly twice as many as the day before.
But the spike was blamed on a technical issue meant cases last week were not recorded properly.
The official dashboard said yesterday that the error has now been resolved but that the total reported over the coming days will include some additional cases from the period between September 24 and October 1.
As of 9am on Friday, there had been a further 6,968 lab-confirmed cases in the UK.
Experts have previously warned that describing the daily figure as a record could be "misleading" as it is not clear how many people were actually infected during the height of the first wave due to a lack of community testing at the time.
Saturday's figure brings the total number of cases in the UK to 480,017.
The Government also said a further 49 people had died within 28 days of testing positive for Covid-19 as of Saturday. This brings the UK total to 42,317.
Other figures show there were 2,194 Covid-19 patients in hospital in England as of Saturday, up from 1,622 a week ago, while 307 Covid-19 hospital patients were in ventilation beds, up from 223 a week ago.
A total of 368 patients with confirmed Covid-19 were admitted to hospitals in England on Thursday, compared with 288 a week earlier.
The Scientific Advisory Group for Emergencies (Sage) has noted that the R number - the rate at which the virus is spreading from person to person - has crept up in the past week.
It is now well over the danger rate of 1.0, with scientists estimating it is nationally between 1.3 and 1.6.
Last night, Labour leader Sir Keir Starmer accused Boris Johnson's administration of having "lost control of the virus", with one in three people in the UK now living under heightened social restrictions.
Sir Keir said the Prime Minister was guilty of "governing in hindsight" and called on the Government to produce a road-map for navigating the country through the winter and to a vaccine.