Two Israeli men were arrested with fake US dollar bills totalling US$5,653 after they exchanged some of them for Thai baht at Samui airport.
Police said Matan Moshe, 25, and Omer Sarusi, 28, were arrested on Saturday.
According to police, the two visitors separately exchanged $50 notes at a Government Savings Bank (GSB) exchange kiosk at Samui airport last Monday. Mr Moshe exchanged five notes for 7,280 baht, while Mr Sarusi exchanged 10 notes for 14,560 baht. The GSB later confirmed the notes were counterfeit.
Police arrested the pair at their accommodation in tambon Bophut and found 48 $100 notes, 17 $50 notes and three $1 notes in their possession.
The suspects told police they had brought the US dollar bills from Israel and were unaware they were fake.
The men arrived in Thailand at Suvarnabhumi airport on Oct 5 on tourist visas.
