Pattaya police rounded up 10 Russian men and women at a hotel room for opening and attending a sex course late Sunday night.
However only four were initially charged for illegal entry, and the rest freed.
The raid at a hotel in Pattaya came after the Transnational Crime Coordination Centre of the Royal Thai Police received tipoff that a group of Russian men and women have opened sex courses in Pattaya.
They charged 20,000 baht for the sex training couses for a trainee.
Investigation later found the sex training course was held at Pattaya hotel room.
The police raided the room where 10 Russian men and women were arrested.
However the Russian instructors claimed they didn’t open the course for Thai people but their own people who were all Russian couples and paid to receive training on voluntary basis to improve their sexual experiences.
They also denied buying sex from Thai women.
Police later detained one of them for overstaying, three for illegal entry and freed the remaining Russians.
Police said they would also charge the suspects who organised the training course for illegal employment.