It is not just police and Customs officers who are on the lookout for cigarette smugglers. Tobacco companies here have also been hiring more private investigators to help tackle a problem which eats into their business.
"It is in our interest as a company to understand how cigarettes are being smuggled into and distributed in Singapore," said Mr Ann Hee Kyet, corporate affairs manager of the biggest tobacco company here, Philip Morris Singapore, which distributes brands such as Marlboro and Next.
Representatives of the other two major tobacco companies - JT International Tobacco Services and British American Tobacco - made the same point to The Sunday Times.
That is where private investigators like John (not his real name), who has been working for tobacco companies over the last decade, come in. Last September, he got a tip-off that a smuggling ring was using a taxi to transport contraband cigarettes here.
After tracking down the cab, he spent days trailing it and keeping a close watch on its activities. The taxi led John to a Singapore-registered van which was also being used to transport illicit cigarettes.
After weeks of surveillance, he discovered both vehicles were repeatedly travelling to a warehouse in Pioneer, which apparently was being used to store the contraband.
"We then passed on this information to Singapore Customs, hoping it could add to the information Customs might have about this syndicate," John told The Sunday Times, on the condition that he not be named.
Last month, Singapore Customs reported its second largest haul of more than 17,600 cartons of contraband cigarettes, worth over $1.6 million, that it seized from two warehouses in Soon Lee Street near Pioneer Road North.
Given that the same pack of cigarettes costs $1.60 in Indonesia compared with $12 here, the price gap will always be a lure for smugglers to bring in the illicit products, said a spokesman for the Tobacco Association (Singapore), which represents the industry here.
A regional study completed last year also revealed that 900 million contraband cigarettes were sold here, depriving the state of around $347 million in tax and putting Singapore at the No. 4 spot in illicit tobacco use in Asia. Revenue from duty-paid cigarettes was $978 million last year.
Added Mr Ann: "No one can really tell how much contraband might be out there, but our previous estimates put it at between 30 million and 40 million packs. This figure could be lower in the light of Singapore Customs' great success in contraband seizures last year."
In its latest annual report, Singapore Customs said it seized 2.9 million packets of contraband cigarettes last year - almost double the 1.5 million packets confiscated in 2012 and up from 1.9 million in 2011.
Despite stringent law enforcement measures, illicit cigarettes still manage to find their way into Singapore.
Said John, who is in his 40s: "Based on what we have seen, the syndicate was smuggling the cigarettes from Malaysia. They were then distributed to various industrial and residential areas across Singapore in vans and taxis.
"After they were divided into smaller quantities, they found their way to illegal peddlers. Some were Singaporeans, others were from countries such as China, Vietnam and Bangladesh."
John, who works with a team of part-time and full-time private investigators, said that his tip-offs come from a range of sources - from the average Joe who gets suspicious of cigarette peddlers in his neighbourhood to members of rival syndicates.
"We also gather a lot of intelligence on the ground. Using a 'cover story' like being tourists or interested buyers, we talk to various people, including those who live or work in the area, and even owners of coffee shops."
He would tail his suspect using different vehicles - a van, a motorcycle or even a taxi. "But there are instances when the suspects get suspicious, in which case we go off. It's a game of cat and mouse."