Officers arrested 29-year-old Russian national Gorskii Matvei while inspecting a Phuket-Pattaya bus entering the province, according to a police report.
Police said the suspect was travelling on a Scania passenger bus on the Phuket-Pattaya route when officers stopped the vehicle at the checkpoint for a routine inspection.
During the inspection, officers observed that Gorskii appeared nervous and agitated upon seeing police. He allegedly attempted to push a bag further underneath his seat and was unable to present his passport when requested, the report said.
Officers then conducted a search of the suspect’s belongings after obtaining consent.
Police seized multiple illegal substances from a shoulder bag he carried, including 564.74 grams of crustal meth, 471.92g of mephedrone, 129.8g of heroin, 51g of ecstasy, 54.6g of amphetamine and 582g of ketamine.
Also seized were two mobile phones, one MacBook laptop and B11,320 in cash.
Mr Gorskii was charged with selling Category 1 narcotics with intent to sell without permission and causing the drugs to spread among the public.
The suspect and all seized items were handed over to investigators at Tha Chatchai Police station for further legal proceedings.
Police said the investigation is continuing as officers work to identify and dismantle any wider drug network.