At 12.15pm of the first day of operations, narcotics officers profiled and performed a search on an unemployed 27-year-old Malaysian man at the checkpoint.

A vigilant officer and his team members proceeded to find two newspaper- wrapped bundles of heroin weighing about 460 grams after checking the battery compartment of the suspect's motorcycle.

The next day at 4.50am, a 26-year-old unemployed Malaysian man was stopped and checked at the checkpoint.

CNB officers then recovered six newspaper-wrapped bundles of heroin weighing about 2800 grams.

 This marked the year's largest single seizure of heroin.

Altogether, about 3.3kg of heroin worth more than $488,000 in street value have been seized.

The Malaysian-registered motorcycles that the suspects used to smuggle the drugs were also seized as part of the operations.

The suspects have been arrested and will be investigated for importing drugs under the Misuse of Drugs Act.

If convicted, they may face the death penalty.

CNB's Director Mr Ng Boon Gay said: “I commend my officers for their vigilance and good work in detecting the drugs. CNB will continue to step up our enforcement efforts at the checkpoints to stem the inflow of drugs into Singapore.”