Tourists have been using Singapore as a transit point to traffic cannabis from Thailand to the United Kingdom, customs officials say.

Samui Customs Office said on Wednesday that many marijuana seizures made between March and September last year were linked to a popular trafficking pattern.

A lot of the cannabis seized was destined to be brought to the UK via Singapore, mostly by British holiday makers.

Travellers appeared to have been undeterred by a warning that UK authorities issued in 2024, stating that they would face serious prison time for bringing cannabis back from Thailand.

The Samui customs office confiscated 406.6 kilogrammes of dried weed from tourists during the seven-month period at Samui Airport, with UK citizens being prime suspects. Its street price was estimated at 4 million baht in Thailand.

A major bust took place on March 12 when authorities inspected suitcases from five UK air travellers and one Malaysian at the airport on the island and found dried cannabis flowers weighing almost 144kg inside.

The official did not say whether the suspects were in the same or separate groups. All admitted to wrongdoing to customs authorities and police upon arrest, he added.