Immigration police on Monday arrested a British man on Koh Samui island and charged him with illegal possession and use of marijuana.
Police said Paul Matthew Kennedy, 32, was arrested on Monday at his home in Bo Phut.
Informants had alleged Mr Kennedy was involved in marijuana-related activities.
They learned from social media that Mr Kenedy had allegedly run a business selling products for growing marijuana in the United Kingdom.
A search of his bag found a small amount of marijuana. Police found marijuana in the drawer of a TV table, and more in a refrigerator.
Mr Kennedy said he bought it for 60,000 baht from a Thai woman.
A urine test confirmed he had used marijuana.
Mr Kenedy was charged with illegal possession and use of marijuana.
