Travellers affected by the Thomas Cook collapse should avoid handing over personal details to websites claiming to be Thomas Cook refund services.
One website ThomasCookrefunds.com was using the Thomas Cook logo and claims to be helping travellers to get their money back.
We asked the domain hosting company to remove the site, and they have now taken it down.
The Civil Aviation Authority (CAA), the official body in charge of processing Thomas Cook refund claims, confirmed the site is a fake.
The fake site encouraged Thomas Cook customers to share their contact details and booking reference in return for help with their refund.
But Thomas Cook is not providing a refund service - it has completely stopped trading.
Which? travel editor Rory Boland said: 'Fraudsters circle like sharks around financial disasters, so people should be aware that there are likely to be fake refund websites set up to fleece Thomas Cook customers - and some of them may look very convincing.
'Refunds for Thomas Cook customers will either be handled by the Civil Aviation Authority from Monday (7 October) or by banks and card providers, so we would urge anyone waiting to claim their money back to ignore alternative websites and unsolicited calls or texts promising a refund.'
We strongly advise against sharing your personal or bank details with organisations you don't know.
Your details could be used to target you with scams that might ask you to send money or bank details.
There is also a chance your details could be used by scammers pretending to be you, in an attempt to claim your refund.
In some cases, those targeted have been asked for payments or bank details.
Claiming a refund through the CAA is free, and you will not be asked for your bank details.
We were unable to contact the people behind ThomasCookrefunds.com, but we've reported the website to the Civil Aviation Authority. We've also asked the company hosting the website to take it down.
Like all fake websites, there are some clues that suggest ThomasCookrefunds.com is not what it might seem.
Bad spelling and grammar, or writing that just doesn't make sense, is a classic giveaway that you're dealing with a fake website.
It's a sign the site was put together quickly and unprofessionally. Content is often copied and pasted from other sites, or is placeholder content that comes with website building templates.
The content shown in the screenshot above likely came as part of the template of the website design, originally intended for a small business website. It doesn't have any relevance to getting your holiday refunded.
ThomasCookrefunds.com lists no contact number or email address. There is no head office address listed, no details about any of its team members and no social media links.
This could suggest the people behind this website don't want to be contacted or identified.
Legitimate companies share their contact details clearly on their websites - they're running a business and want people to get in touch. In the UK it's a legal requirement for businesses to list a registered business address on their website.
Featuring endorsements from reputable organisations or media outlets is a common way for companies to show they're credible.
But fake sites often use well known brand logos without permission, or create fake ones to try to look genuine.
When checking ThomasCookrefunds.com, we found that 'Asia' doesn't exist as a travel group. As far as we know, the continent of Asia is not involved with the Thomas Cook refunds service.
Club Marmara is a real holiday resort group, but have confirmed they have no partnership with any company processing Thomas Cook holiday refunds.
There is no proof that 'Oliver Hall' exists. Oliver is not pictured, and the supporting quote is generic, containing no facts or details that support a true story.
It's possible to find out who owns a website by carrying out a Whois search. This gives you access to a public database containing information about internet domains, including details about who owns them.
However, the identity of the ThomasCookrefunds.com creator has chosen to be masked, which suggests they want to remain anonymous.