Their motorcycles had also been seized, the agency was quoted as saying by Channel NewsAsia.
On Wednesday, CNB officers checked the battery compartment of a motorcycle at the Woodlands Checkpoint and found two bundles wrapped with newspaper, containing about 460gm of the drug. The 27-year-old motorcyclist was arrested.
Yesterday, CNB officers searched a motorcycle and recovered six bundles wrapped with newspaper, containing heroin weighing about 2.8kg and arrested the 26-year-old motorcyclist.
CNB said the unemployed duo would be investigated for drug importation under the Misuse of Drugs Act.
If convicted, they may face the death penalty.