A mistake at a lab which saw thousands of positive COVID-19 cases reported as negative could have led to the deaths of 20 people, according to new estimates.

The error at Immensa Health Clinic Ltd in Wolverhampton meant around 39,000 PCR tests were reported as negative when they should have been positive between 2 September and 12 October 2021.

Most of these cases were in the south-west of England.

As a result, many people would have continued with their daily lives and not self-isolated even though they had COVID-19.

Experts from the UK Health Security Agency (UKHSA) have estimated the error led to about 55,000 additional infections, with each person who received a false result going on to infect an average of two other people.

Researchers also estimated that there were about 680 additional hospital admissions “that may not otherwise have occurred”.

“Similarly, we estimate that there may have been just over 20 additional deaths in these most affected areas,” they added.

£170m government contract

Immensa was given a £119million government contract in October 2020 to urgently “develop volume for PCR testing for COVID in line with test and trace requirements”.

The firm was later given another £50m contract to facilitate additional testing capacity.

Reports in The Sun at the time featured footage of staff at the lab appearing to fight, drink alcohol and play football.

The UK Health Security Agency’s (UKHSA) chief executive Dr Jenny Harries said: “I fully accept the findings and recommendations made in this report, many of which were implemented as soon as UKHSA discovered the incident.

“These ongoing improvements will enhance our ability to spot problems sooner where they do arise.”