About 4,000 boxes of contraband cigarettes were found in a truck with "air conditioners" at Tuas Checkpoint last Thursday.
The Immigration and Checkpoints Authority (ICA) said yesterday in a Facebook message that agents notice anomalies in the scans of the shipment that passes through the checkpoint.
The shipment in the truck registered in Malaysia was declared as air conditioners, ICA said.
The vehicle was driven by a 47-year-old Malaysian driver. Officers carried out further checks and revealed the cigarette contraband.
ICA said the case was referenced for further investigations into Singaporean customs and added: "This way of concealing is a cause for concern because similar methods can be used by people who do not want to smuggle security items to Singapore."