A boat crew member has been arrested and charged with raping a British tourist on Koh Phi Phi this week.
Deputy police spokesman Krissana Pattanacharoen said the man, whose name was withheld, was arrested on Wednesday on the island off the coast of Krabi.
The suspect was apprehended after police examined security camera recordings and other evidence.
The 21-year-old Briton, whose identity was also not disclosed, registered a complaint alleging sexual abuse with police on the island on Monday.
She said she could not remember the attacker as the assault occurred while she was drunk and asleep outside a hotel restaurant on Loh Dalum beach, Pol Col Krissana said.
The woman said she was travelling in Thailand alone but went out with an Irishman for drinks on Sunday night. They were returning to their hotel after the bar closed at 1am on Monday but ended up sleeping outside a beachside restaurant at another hotel, she said.
Pol Col Krissana said the woman was sent for a physical examination on Monday to check for traces of sexual assault.
Meanwhile, police have detained a man on suspicion of murder after a woman he had sex with was found dead on Jomtien beach in Pattaya yesterday morning.
Wichai Thaengthong, 45, was arrested hours after the body of a 45-year-old woman was discovered by a worker at a beachside restaurant.
The dead woman was naked from the waist down. Mr Wichai said he had consensual sex with her on the beach but claimed that during the act she had a convulsion and died. He denied murdering her.