UK MPs have been told hundreds of people, mostly workers transporting goods, are trying to enter the country with fake COVID-19 test certificates.
To enter the UK, people have to show proof of a negative test taken up to three days before departure. Proof of a negative test has to be provided to border staff as either a printed document, email or text message.
Immigration Services Union boss Lucy Moreton told the UK All Party Parliamentary Group on Coronavirus earlier this week documents are very easy to forge and it wasn't possible to know the number of people with fake documentation who are not being caught by officials, UK media reported.
Currently 20,000 people are entering the UK daily, the majority being in the transport sector. Moreton claimed more than 100 fake certificates are being caught each day.
Moreton said verifying documents was largely based on trust. She claimed the forged documents were mostly identified through spelling mistakes, but said it is difficult when they are in a foreign language.
The official said if they are not in English and the border workers are unable to understand the language in the documentation, it is taken at face value.
Border force officials have a list of serial codes which they can check against but they are easy to forge, Moreton told the group.
The UK reported another 33 deaths and more than 2500 cases of COVID-19 on Tuesday.
More than 30 million people in the UK have received their first vaccine dose as the race continues to beat the pandemic.