A British woman was raped on the holiday island of Koh Samui, a spokeswoman for the Thai Tourist Police said today.
She said the attack happened over the weekend but could not confirm exactly when.
She said: "A man was arrested within 12 hours of the incident and is being held."
The Daily Mail reported that a 21-year-old local taxi driver was in custody after the attack near Lamai Beach.
Deputy Police Commander Paiboon Krajakchan said the woman was robbed and dumped beside the road by another man after the attack.
He told the newspaper: "We are treating this matter seriously. It is important that Koh Samui is seen as a safe destination for tourists."
Koh Samui was the scene of an infamous case on New Year's Day 2006, when British tourist Katherine Horton was raped and murdered on Lamai Beach by two fishermen.
The 21-year-old from Cardiff was attacked on the beach
The two men were found guilty of her murder and initially sentenced to death, but their punishment was later changed to life imprisonment on appeal.
A Foreign Office spokeswoman said: "We are providing assistance to a British national in Koh Samui, Thailand."