Covid-19 case numbers increased more than 15 percent across England in the most recent week measured, according to a weekly infection survey released Friday, after the government relaxed virus curbs.
The figures for the week ending last Saturday contrast with the health ministry's daily testing data, which registered dramatically declining cases during much of last week.
The recorded halving in new daily cases, which has since gone into reverse, surprised officials and experts who had predicted the July 19 removal of remaining pandemic rules would prompt a surge in infections.
However, the latest survey by the Office for National Statistics (ONS) - which is seen as more reliable as it randomly samples the population - suggests cases may not have fallen and that daily testing failed to detect many new infections.