WASHINGTON (REUTERS) - A unit of Abbott Laboratories is recalling two Covid-19 test kits as they can potentially issue false positive results, the US Food and Drug Administration said on Thursday (Oct 14).

The regulator has identified the recall of the Alinity m SARS-CoV-2 AMP and the Alinity m Resp-4-Plex AMP laboratory test kits by unit Abbott Molecular Inc as a Class 1 recall, the most serious type.

The agency in September issued a letter cautioning healthcare providers and clinical laboratories of a potential for false positive results with the two tests, and recommended they consider retesting positive patient samples with another authorised Covid-19 test.

An overflow of one patient sample into another while mixing chemicals with the samples could be related to the false positive results, the FDA said on Thursday.

The agency said no deaths or adverse health consequences have been reported from use of the tests.

Abbott has a range of FDA-authorised Covid-19 tests, including antigen, molecular and serology, which helped boost its revenue during the peak of the pandemic last year.