Hongkongers going away for the holidays are being told to stay away from drugs, even if they are legal in other countries.

A government statement on Monday particularly singled out cannabis – which was recently legalised in Thailand – warning it can even be found in the form of food, drinks, health supplements or skincare goods.

"Products that are marked with the words 'CBD', 'THC', 'cannabis', 'cannabinoids', 'ganja', 'hemp extracts', 'marijuana' or with a picture of a cannabis leaf may contain substances that are illegal in Hong Kong or prohibited at the transit airports," said a spokesman for the Security Bureau's narcotics division.

"When in doubt, travellers should not take the risk of consuming these products or bring them back to Hong Kong."

The SAR will list CBD, a chemical derived from cannabis plants, as a dangerous drug from February 1 next year and products containing the substance will be prohibited.

The statement also included a warning on drugs in general from Donald Li, the chairman of the Action Committee Against Narcotics.

"While gradual resumption of normal travel is welcome by everyone, don't let holiday mood bring you lifelong regrets. Trying something new during travel does not mean you have to try drugs. Don't let drugs get into your life," Li said.