A team of scientists has issued a warning after a study found that a popular antiviral drug used to treat Covid is triggering mutations of the virus.

The drug, molnupiravir, is driving an unintended pattern of mutations in the SARS-CoV-2 virus that is increasing its genetic diversity and causing it to spread, the scientists warn.

This is the warning of an international team of researchers who studied some 15 million SARS-CoV-2 sequences.

The study sought to map out exactly how the coronavirus has mutated over time.