Railway police on Tuesday found one kilogramme of crystal methamphetamine, or "ice", stashed in a carriage on the Butterworth-Bangkok express train during a stop at Hua Hin railway station in Prachuap Khiri Khan province.
Pol Maj Tham Loysatheun, an inspector of Hua Hin railway police, said the train was searched when it stopped at the station about noon.
They found the drugs, in a tape-wrapped plastic bag, under a vacant sleeping berth.
Pol Maj Tham said the drugs might have been hidden under the sleeping berth for the trip from the South to Hua Lampong railway station in Bangkok, where they would be picked up.