The tourist visited the hospital on Phi Phi Island to get a checkup on March 6 after she thought she had been raped overnight.
But the case came to a halt when the tourist was unable to remember any details of the incident.
Pol Lt Col Amorat Suthikait, of Krabi Police, told The Phuket News the tourist could not remember details.
“She said she was drunk and fell asleep on the beach. We took her around some places around Phi Phi island to try and trigger her memory, but she still cannot remember,” he said.
The tourist returned to her home country yesterday.