British automotive services company RAC has said that the government must do more to investigate untaxed foreign vehicles, warning that they could be draining the UK of millions of pounds every year.
It said that while an estimated 60,000 foreign vehicles are registered with the Driver and Vehicle Licensing Agency (DVLA), a further 15,000 are not: that's one in five that are unregistered, which leads to an estimated loss of £3m annually.
The DVLA is the government organisation responsible for maintaining a database of drivers and vehicles in the UK. One of its main duties is to collect vehicle excise duty, or road tax, from those included in the database.
At present, the law requires all foreign vehicles to register with the DVLA after being in the UK for six months. Once registered, they will be taxed and insured.
The problem, according to the RAC, does not stem from the UK Border Force's monitoring of foreign vehicles entering and leaving the country, but rather from a lack of communication and the DVLA's failure to check foreign vehicles that are known to be in the country.
Pete Williams, head of external affairs at the RAC, told the BBC that the situation was "beyond belief".
"Given the prevalence of technology such as automatic number plate recognition, it is beyond belief that in the 21st century two important government agencies - namely the UK Border Force and DVLA - are not already sharing information," he said.
"We understand that DVLA, the UK Border Force and the police are looking at how data can be used to identify foreign-registered vehicles that have been in the UK for longer than six months, so we urge the government to make finding an effective solution a high priority."
According to a spokesman for the Department for Transport, the government has said that it will shortly announce plans to combat the problem, including ways to improve information sharing.