Spanish police said they had detained seven suspected members of an international criminal gang that created and sold forged Covid-19 passports and negative tests.

The Spanish arm of the ring, which advertised its services on “anti-vax” instant message groups, fraudulently added at least 1,600 people to the national vaccination register with the help of health workers, the investigation found.

European Union countries agreed last year to create a standardised Covid certificate with a QR code so vaccinated and tested people could travel and attend events.

According to Reuters, that created a demand for forgeries.