Hong Kong Customs on Friday seized about 6 kilograms of suspected ketamine and 5 kilograms of suspected cannabis buds from two flight passengers.
The estimated market value of the seized items is about 3.4 million dollars.
Two men were arrested.
The passenger who carried suspected ketamine inside his check-in suitcase was a 22-year-old British man travelling from the Netherlands.
Another passenger is a 41-year-old Chinese man coming from Thailand, and Customs officers found the alleged cannabis buds in his suitcase.
Under the Dangerous Drugs Ordinance, trafficking in a dangerous drug can receive a maximum fine of 5 million dollars and life imprisonment.