A drug bust this week saw the authorities seize 2.92kg of heroin, enough to feed the addiction of 1,390 abusers for a week.
The Central Narcotics Bureau (CNB) arrested eight Singaporean men in the operation on Monday and Tuesday, in which some methamphetamine, also known as Ice, was also recovered. The drugs seized are estimated to be worth at least $215,000 in total.
On Wednesday, CNB provided details of the operation, which included its officers forcing their way into a fifth-floor Housing Board unit near Boon Lay Drive to arrest two of the suspects.
CNB officers had tailed several of the suspects from a rendezvous point near Wellington Circle in Sembawang on Monday.
As the officers looked on, a white car pulled up near a waiting van and a man emerged to hand over a black package to a passenger in the van.
Officers then followed both vehicles as they made their way to Simei, Bukit Batok and Woodlands.
Along the delivery route, passengers in the white car met other suspects, who in turn went to Boon Lay and Ang Mo Kio.
Officers later raided flats these suspects had been seen in and discovered drugs were stashed there.
One of them, a 50-year-old, was stopped at the void deck of an HDB block in Ang Mo Kio and was found with 1.91kg of heroin stored in four clear plastic bags.
Cash worth $6,460 was also found on him.
Investigations into the case are being carried out.