Private investigator Paul Jones of ARF Investigators said holiday scams are "becoming very sophisticated". Mr Jones said: "We've seen everything from fake listings to fake booking websites that look completely legitimate.

"And if you get caught, you could end up paying thousands of pounds for something that doesn't exist." One of his professional tips is to question a holiday deal that seems too good to be true. "Only book your holiday through a trusted online provider and never take anything off the platform," said Mr Jones.

"If they suggest you chat on WhatsApp or an equivalent and then ask for additional payment, do not send them money and report them to the booking provider."

Mr Jones said fraudsters "often ask for bank transfers or PayPal transfers," but you shouldn't send money like that.

"When paying on a platform, make sure to pay with a credit card, which gives you an added layer of security," added Mr Jones.

One way to determine whether a website is legit is to conduct a "reverse image search."

Mr Jones said: "In our experience doing a reverse image search is a great way of finding out if you are being scammed or not."

All you need to do is take an image from the holiday listing and drag it into a Google search to discover if the image has been used elsewhere across the internet.

Mr Jones elaborated: "While it's not 100% effective, what it does is show you if the photos have been used in the past for different addresses.

"If the image comes up for more than one address, then you are being scammed."

What to do if you've been scammed

Anybody who has experienced a holiday scam is encouraged to contact their credit card company to have the money returned.

However, if you paid by PayPal, you'll need to open an active fraud investigation; those who paid by bank transfer are unlikely to get their money back.

Mr Jones said: "It's important to slow down when making an expensive purchase; holidays are exciting, but take it slow, double-check everything, read reviews and trust your instincts.

"These holiday scams are convincing, and anyone can be scammed; don't think it won't happen to you, because when it does, you will lose thousands."