The Office of Fair Trading has vowed to investigate websites that are charging fees for Government services that have little or no fees.
Last year the OFT shut down four websites that were to be charging fees for the free European Health Insurance Cards (EHICs).
They will look at websites that are charging excessive fees for driving theory tests, as well as selling EHICs.
Cavendish Elithorn, of the OFT, said: "It is important that companies are clear about the service they are offering, and do not trick people into paying for something that they can get for free or much cheaper on government websites."
"We will be considering whether any of the sites under investigation are misleading consumers," he added.
For more information visit the Office of Fair Trading website.
Get your EHICs from EHIC.org.uk for free.
