Four men were nabbed and more than 1,000 cartons of duty-unpaid cigarettes were seized following two related operations mounted by Singapore Customs officers on Monday and Tuesday.

Chinese national Xu Songxin, 32, and three Singaporeans were arrested in the operations, and a total of 1,024 cartons and 710 packets of duty-unpaid cigarettes were seized.

These amounted to about $96,140 of duty tax and $7,060 of goods and services tax evaded, the Singapore Customs said in a statement yesterday.

On Monday, Customs officers saw Xu leaving a unit at a Holland Road condominium and walking towards the staircase landing.

They moved in to check on him and later searched his room in the unit, where they found 260 cartons and 421 packets of duty-unpaid cigarettes. He was arrested, and the items were seized.

Investigations revealed that he had stored the duty-unpaid cigarettes in the room while waiting for further instructions on delivery.

A related investigation led Customs officers to launch another operation the next day.

They trailed a car to a Jurong West Street 41 carpark and saw the male driver parking the vehicle next to a van.

Two other men then approached the vehicles to transfer a box from the van to the car.

Officers moved in for checks and found 764 cartons and 289 packets of duty-unpaid cigarettes in the two vehicles.

The items were seized and the three men arrested for their suspected involvement in duty-unpaid cigarette activities.

On Wednesday, Xu was sentenced to six months in jail for storing the duty-unpaid cigarettes.

Investigations are ongoing for the other three men.

The Singapore Customs said in its statement that buying, selling, conveying, delivering, storing, keeping, having possession of or dealing with duty-unpaid goods are serious offences.

"Offenders will be severely dealt with. They can be fined up to 40 times the amount of duty and GST evaded and/or jailed for up to six years," it added.

Repeat offenders caught with more than 2kg of tobacco products will also face mandatory imprisonment, while the vehicles used in the commission of such offences may be forfeited.