Almost 7,000 cartons of contraband cigarettes were seized from a Malaysia-registered container truck at the Tuas Checkpoint early yesterday.
Officers from the Immigration and Checkpoints Authority (ICA) had directed the lorry, which had a 40-ft container, to undergo routine checks at about 1.20am.
During the inspection, 6,750 cartons of duty-unpaid cigarettes - each containing 10 packs of 20 sticks - were found hidden among consignments of various items such as food and plastic ware.
The truck was driven by a 44-year-old Malaysian man, who was assisting in investigations yesterday.
The contraband cigarettes and vehicle were handed over to the Singapore Customs for investigations.
The potential duty and Goods and Services Tax evaded amounted to about $523,800 and $49,990 respectively.
The vehicle used in the commission of the offences is liable to be forfeited.
The ICA said it will continue to conduct security checks on vehicles and passengers at checkpoints to "prevent attempts to smuggle in undesirable persons, drugs, weapons, explosives and other contraband".
It added: "The same methods of concealment used by contraband smugglers may be used by terrorists to smuggle arms and explosives to carry out attacks in Singapore."