This brings "buyer beware" to a new level.
Reports are coming in from consulates around the world of a scam perpetrated by international airport duty free shops and local cops. Here's how it works:
While awaiting your international flight at the gates of an international airport, you go shop in a duty-free store. These are common and popular because they do not charge sales taxes to those immediately leaving the country with the goods.
The scam begins, as is so often the case, with the cashier. She either (a) adds something to your bag, such as an additional bottle of perfume, or a second carton of cigarettes. These items can easily be mistaken for promotional, as duty free stores often engage in this kind of marketing.
Next, after you have left the store and are walking around the gate area or to your flight, the sales clerk calls her accomplice, the local cops. The clerk provides your complete information and says you stole the extra bottle of perfume. The cops have an easy job of finding you at the international terminal, especially when you need your passport to get on the plane.
The finale is when they stop you, and you happily show the receipt for your goods. They then point out that you have a stolen bottle of perfume, and you are held - incarcerated.
This tactic has been reported in parts of east and central Asia, and Central America, but it could happen anywhere a cop can take a bribe. Because it is so clean, easy, predictable, safe for the conspirators and profitable, I expect it could spread like wildfire.
How to stop this from happening to you:
Don't leave the duty free store unless your receipt matches exactly the items in your bag. If there are legitimate gifts, they must also be identified as such on the receipt.