UK holidaymakers returning from their summer break are being warned they face prosecution if they make fake sickness claims against tour operators.
Travel trade organisation Abta says claims firms are wrongly telling the public there is no risk if they seek compensation despite not being unwell.
People are being bombarded by cold callers and social media messages with requests to submit claims after they get home from an overseas trip, according to Abta.
The penalties for those caught include a fine, criminal record and potential imprisonment either in the UK or in the destination of their holiday, the travel organisation added.
Holidaymaker Tracey Krieger, of north-west London, recently returned from an all-inclusive break in Mexico and received several phone calls from claims firms when she was back in the UK.
She said: "I've been cold-called by companies asking if I became sick while I was on holiday and telling me how easy it is to claim compensation.
"I even get messages and adverts on my Facebook page - it is getting to be just like whiplash and PPI (payment protection insurance).
"It really annoys me that these companies can get away with this, it is dishonest and we will all end up losing out as this will cause holiday prices to rise."
Tens of thousands of UK holidaymakers have made claims in the past year despite reported sickness levels in resorts remaining stable.
Since spring 2016 travel firm Tui has recorded around 15 times more illness claims than in previous years.
They are typically worth around £3,000 to £5,000 - which is more than the cost of many of the holidays involved.
Abta chief executive Mark Tanzer said: "Holidaymakers need to understand that making a fraudulent claim will have consequences.
"People tempted to fabricate holiday sickness in order to make a claim should be aware that this is a crime and that they risk ending up in jail either in the UK or abroad.
"People should be very wary of any company that approaches them and encourages them to make a dishonest or exaggerated claim. Whatever a claims firm might say, fake claims are fraud."
In July the Government announced plans to reduce the incentives of bringing fake cases.
Under these proposals, tour operators would pay a prescribed sum depending on the value of the claim, making the cost of defending cases predictable.