A man suspected of selling fake Covid test certificates has been arrested at Luton Airport.
Several countries served by the airport, including Italy and Bulgaria, require proof of a recent negative test from all international arrivals.
Travellers arriving in the UK face the same requirement to be allowed entry.
The suspect, in his 30s, was arrested on suspicion of fraud by false representation and released under investigation.
Anyone with information is asked to contact Bedfordshire Police.
Det Sgt Tom Hamm said: "Unfortunately, fraudsters have seen the ongoing pandemic as an opportunity to prey on people, and if you are approached by someone offering to sell certificates who is not an authorised provider, please report it immediately."