A group of Thai people approached the tourist after he left a convenience store late last week, the Thaiger news portal reported. The group then distracted him by asking him about what he bought and about his holiday in Thailand.
He suspected one of them had pickpocketed him; he did not explain why he was carrying such a large sum of money with him at the time.
Police said CCTV footage from the store and other cameras nearby would be reviewed to try to identify and arrest the suspects.
Thailand welcomed 11 million foreign visitors last year thanks to its open visa policy, making its tourism industry among the fastest in the region to recover following the Covid-19 pandemic.
The Thai government is targeting 30 million arrivals this year.