The Central Narcotics Bureau (CNB) seized over $115,000 worth of drugs - enough to sustain 512 abusers for a week - and more than $28,800 in cash in an operation on Wednesday.
The haul comprised 1.07kg of heroin and 18g of 'Ice', said the CNB in a statement on Thursday.
At about 1pm on Wednesday, officers stationed around Handy Road spotted the first suspect, a 51-year-old Singaporean man, getting into a black car. About five minutes later, the car dropped the man off at Grange Road and drove off with the two other occupants, the 38-year-old driver and a 43-year-old passenger.
A party of officers kept track of the car's movements, while others moved in to arrest the first suspect, who was carrying a sling bag with about 1,047g of heroin, 18g of 'Ice', $13,430 in cash and a digital weighing scale. He also had more than $2,300.
At about 1.30pm, the black car stopped at the junction of Tanjong Katong and Mountbatten roads. CNB officers moved in on it and arrested the two Singaporean men in the car, recovering $13,050 from inside the vehicle.
About 27g of heroin, a digital weighing cale and other drug paraphernalia were also recovered from the home of the 38-year-old driver.
The three suspects are currently being investigated for drug trafficking activities. A follow-up operation later that day saw six suspected drug abusers - two women and four men, all Singaporeans - arrested.