The Central Narcotics Bureau arrested three Malaysian men aged between 23 and 28 following the search of the vehicle on Wednesday, which uncovered 17.7kg of heroin, 261gm of crystal methamphetamine and 2gm of ecstasy pills.

The driver was detained at the scene and the other two men, believed by officers to be the intended recipients, were arrested the following day.

Singapore has some of the world’s toughest penalties for drug trafficking, including execution by hanging.

The trafficking of more than 15gm of pure heroin or 250gm of methamphetamine can result in the death penalty. Human rights groups say hundreds of people have been hanged for drug offences over past decades, including many foreigners.

The narcotics agency estimated the street value of the drugs seized to be about S$1.3 million (RM4.4 million).