LONDON, (Reuters) – A COVID-19 laboratory has been closed in central England due to concerns that it was incorrectly giving false PCR results to infected people. The UK Health Security Agency (UKSHA), announced Friday.

After reports that people had received negative results from PCR tests after being tested positive for rapid lateral flow (RLVDs) in Wolverhampton, NHS Test and Trace began an investigation.

The government advises that PCR tests prove to be more reliable than LFDs and can help people stop self-isolating in the event of a positive LFD followed by a negative test.

UKSHA stated that 43,000 people could have received incorrect PCR results. This was mainly South West England. It is possible this underestimated the coronavirus population between Sept. 8 and Oct. 12.

“We immediately stopped testing at this lab while we investigate,” Dr Will Welfare (Public Health Incident Director).

There is no evidence that PCR or LFD test kits are defective. The public can continue to use them as well as other services provided by the laboratory.

Immensa Health Clinic who runs the laboratory said they “fully collaborate” with UKSHA on the investigation.

UKSHA claimed that the incident was isolated in one laboratory and that samples have been redirected to others.

This meant that the Immensa Lab was only part of the nationwide network. Overall testing availability was therefore unaffected. People who have a positive LFD should still get the results confirmed using PCR.