The cough syrup was reportedly on its way to the deep South, where it is made into the “4×100” stimulant cocktail popular among youngsters, that is made of four main ingredients – krathom leaves, cough syrup, Coca-Cola and ice.

Police also arrested 10-wheel-truck driver Apinan Kuanoon and seized some Bt450,000 in cash from him.

Dusadee’s deputy Pol Colonel Watchara Thipmongkol said police had received a tip-off from an informant that the truck would carry cough syrup from Bangkok to a destination in Nakhon Si Thammarat. So, they set up a checkpoint on Phetchkasem Highway in Chumphon and arrested Apinan, who failed to show a delivery order or any document for possessing such goods, at 11pm on Thursday.

When Apinan was arrested, his hirer, identified only as a woman nicknamed “Tim” called Apinan’s cell-phone to offer the police Bt450,000 in cash in exchange for release of the suspect and the cough syrup. Apinan told police that Tim hired him for Bt13,000 to pick up goods including the syrup from a company in Bang Bon in Bangkok to deliver to the South.

Watchara said the syrup batch was in three bottle sizes – large bottles that cost Bt50 but able to fetch Bt300 each, mid-sized bottles that cost Bt20 but sell for Bt120 each, and small bottles that cost Bt10 but are sold for Bt40 each.

Apinan was passed on to Salui Police Station to face the charge of possessing a dangerous medicine with intent to sell without permission and conspiring with others to bribe police.