Europol has warned EU authorities to be on the watch for organised crime gangs selling fake Covid-negative test certificates at airports, sometimes for as much as 300 euros each.
Monday's warning issued by the EU law enforcement agency comes after police arrested several suspects selling forged certificates declaring people had tested negative for Covid-19 at airports in France and the UK, as well as online and through mobile chat groups in Spain and the Netherlands.
Many EU countries now require proof that passengers are not infected by the disease, which has killed more than 2.2 million people worldwide.
"As long as travel restrictions remain in place due to the pandemic, it is very likely that criminals will seize the opportunity of producing and selling fake Covid-19 test certificates," Europol said.
"Given the widespread technological means available in the form of high-quality printers and different software, fraudsters are able to produce high-quality counterfeit, forged or fake documents," the Hague-based police agency said.
RFI requested further information on the nature of the criminal operations and proposed measures to tackle the racket, but Europol declined to expand on the statement.
The warning "describes a new phenomenon in Europe", the agency said, adding that it was waiting for feedback from EU Member States "to develop the full intelligence picture on the phenomenon".
Late last year, French police broke up a forgery ring at Paris' Charles de Gaulle airport selling fake certificates for 150 to 300 euros.
According to Europol, recent intelligence suggests that in the UK, fraudsters were caught selling bogus Covid-19 test documents for £100, faking the name of a genuine laboratory on the false certificates.
In Spain, police arrested a man selling forged papers online for 40 euros. In the Netherlands, scammers were doing the same via mobile messaging applications.