Christmas shoppers looking for a bargain should be wary of counterfeit goods which flood the market in the run-up to the festive season, the UK Border Agency has warned.

Fake Ugg Boots, GHD hair straighteners, iPhones and iPads are among the tens of thousands of counterfeit items that have been seized by officers as they have been brought into the country in recent months.

Buyers can be left with products which are at best, inferior to genuine ones and, at worst, harmful or unsafe, Grant Miller, from the UK Border Agency's Heathrow International Trade Division, said.

He added: "We are uncovering all sorts of fake goods, from beauty products to children's toys, and we're warning people to be particularly wary of buying cheap items online or from unofficial traders. It's easy to be tricked into thinking you're getting a bargain, but in the run-up to Christmas our message is that if something appears too good to be true it probably is."

Immigration minister Damian Green said: "We are dealing with a huge criminal business. The international trade in counterfeit goods is serious organised crime and, for the gangs behind it, it is low-risk and high-reward.

"Intellectual property crime is a serious economic threat, and it's estimated to be worth around £1.3 billion in the UK each year. That is why we have UK Border Agency officers operating 24 hours a day at ports, airports and mail sorting centres and they have seized thousands of counterfeit items that could otherwise have ended up as gifts this Christmas."

Trading Standards Institute chief executive Ron Gainsford said: "In this difficult economic climate money is tight for many of us, but there could be a high price to pay for bargain presents that aren't the real deal.

"Trading standards are working hard with other authorities to stop criminals ruining consumers' festive spirit as millions of low-quality and potentially dangerous counterfeit products are flooding the country in time for Christmas, particularly in markets, car boot sales and online.

"The external appearance and packaging of electrical goods such as chargers and hair straighteners may be copied fairly well, but the internal composition and materials are likely to be substandard and could make the item very dangerous. Similarly toys, jewellery, alcohol and cigarettes might look the part but could turn out to be toxic.

"Check, double check and check again to make sure what you are buying and where you are buying from is the real deal."