Rip-off websites dominated the results when Which? Travel investigated common search terms for travel on Google earlier this year.
Three out of six of the top search results for the new, post-Brexit health card (Ghic) were firms charging for the card, which is free from the NHS. The companies had bought adverts from Google to appear at the top of the page.
Other rip-offs included opportunists selling almost worthless translations of driving licences.
And criminals were even paying Google for adverts explicitly touting fraudulent driving licences for travel in Europe.
There were also outrageous surcharges for buying visas or visa waivers further afield, including for the US and Dubai.
Since our intervention, through this and other Which? investigations, Google has stopped dozens of copycat websites advertising, although they can still appear lower down in search results.
We've reported in the past on companies charging as much as £30 for the European Health Insurance Card (Ehic), which was always available free from the NHS.
Since Brexit the card, which allows access to free or subsidised health care in most European countries, has been replaced by the Global Health Card (Ghic). While the Ehic is still accepted, once it expires British nationals need to apply for the Ghic.
We approached Google in January to point out that it was accepting adverts from , with spurious claims of providing assistance in making the application. This was against Google's own terms and conditions. It agreed and told us:
'We have strict ads policies that govern the types of ads and advertisers we allow on our platforms. Under our policy, we only allow Governments or their delegated providers to advertise for official documents or services. When ads breach our policies we take action to remove them.'
Despite this, other search terms also exposed travellers to the risk of being ripped off. Prior to Brexit there was speculation that UK drivers would need to get a new permit to drive in Europe after the end of the transition period. In fact, only those with an old-fashioned paper licence need to apply for the International Driving Permit (IDP), which costs £5.50 from the Post Office.
But when we googled International Driving Licence, we found several firms using Google ads that were claiming the opposite. One, called the International Drivers Association, says on its website that you need an 'International Driving Permit' to drive in Spain, which it will sell you for $49.
However, elsewhere on its site, it confirms that its product is just a translation of your licence into other languages and it doesn't have any legal status.
When we challenged it on this, the International Drivers Association told us that, if UK customers ask them, it does explain that they don't need to buy an IDP for trips to Spain. It also said: 'We're 100% transparent and upfront with our customers; we do not claim to sell a government document.'
Fraudsters running a site called alleudriverslicense.com were even able to buy a Google advertisement that explicitly sold a 'European driving licence without a test'.
It appeared at the top of the page when we searched for 'European driving licence'.
We contacted its live chat service and pretended to have been banned from driving and it said that for u20ac800 it could use its contacts in the DVLA to wipe out our ban and get us a new, clean licence.
We reported this to Action Fraud, but two weeks later the site was still live. We also reported it to the DVLA and Trading Standards, and finally it disappeared.
We also found ads for sites selling expensive visas for Dubai and other United Arab Emirates (UAE) destinations. One site charged $189 for just two weeks in the country. But if you have a British passport you don't need to apply for a visa in advance to travel to Dubai. You can get one on arrival and its free.
The official UAE government website that will tell you this, u.ae/en, was buried below seven other websites when we looked on Google.
We found similar rip-off websites trying to sell more expensive or unnecessary visas for Egypt, Nepal, New Zealand and Turkey, too.
There was also a firm blatantly imitating the official United States government site, in order to add a massive surcharge to the visa waiver card, Esta. All British travellers heading to the States need to fill in the Esta form, which costs $14 from the official site esta.cbp.dhs.gov.
But when we looked on Google, the top site was an advert for the very similar-looking esta-cbp-gov.com. The latter charges $88. Another copycat site, Esta-visatravel.com, charges 'up to $111'. They both include small disclaimers that they're not affiliated with the US government. Neither responded to requests for comment.
We approached Google about the adverts that we'd discovered in March and it removed 18 of them. Six weeks later, we looked at the same search terms and found 14 similar or identical Ads, which Google also removed.
Currently, although there are fewer copycat websites when you search for Ghic, Dubai visa and Esta, they still exist. On our most recent search, the dubious adverts for International Driving Licences or permits had all been removed.
Google says it blocked or removed more than 3.1 billion ads last year, nearly 5,900 a minute.