England's government agency responsible for responding to public health emergencies said mistakes at a testing laboratory resulted in tens of thousands of positive COVID-19 cases being reported as negative and may have led to the deaths of 20 people.

An investigation by the UK's Health Security Agency found that the Immensa laboratory in central England misreported around 39,000 tests between September 2 and October 12, 2021 as negative when they should have been positive.