KOH SAMUI — A British businessman on Koh Samui ran foul of the law Wednesday for innovating in the kitchen by adding cannabis to his tom yum goong.

Gary Coughlan, 58, was arrested and charged with drug offenses this morning after policemen noticed he was acting erratically, police told reporters. They said he tested positive for drug use.

Police said Coughlan, a real estate developer who has been living on Koh Samui for 22 years, confessed to eating the spicy shrimp curry infused with marijuana prior to his arrest, citing its benefits for good sleep. He said a Thai friend provided the substance.

Although the interim parliament recently passed a law legalizing medical marijuana, unsanctioned use of the plant remains illegal. Violators face jail time of up to a year.