Electronic cigarettes are banned here but that has not stopped more smokers from trying to get hold of them and even using them boldly in public.
In the first five months of the year, the Health Sciences Authority (HSA) seized 2,428 units of the smokeless product. This is far more than the 1,464 it detected in the whole of last year. In 2009, only 10 were confiscated.
Local users are able to buy e-cigarettes from overseas websites or when travelling in countries that permit their sale.
They have taken to calling themselves "vapers" - in reference to the nicotine-laced vapour that is a hallmark of the device. Some even get their stash from underground local suppliers.
One such Singapore-based seller said there is demand, and fresh stock is brought in every week.
The battery-run steel tube creates vapour from heating liquid nicotine, which is then inhaled. Developed in China in 2004, it can be recharged and used repeatedly, by putting in a new cartridge of liquid nicotine.
One cartridge usually has enough nicotine to last several hours to days, depending on the smoker's habit. A starter pack can usually be bought for $100 or less.
Global sales are climbing, backed by the belief that they are healthier than regular cigarettes and could help smokers quit.
The growing popularity of "vaping", as the practice is known, appears to be rubbing off here as well, with a local Facebook community page set up last year.
Checks with several websites based in Britain and Malaysia confirm they ship to Singapore.
Online forums are another avenue where participants buy, sell or trade e-cigarettes on the sly. They do this despite knowing of the ban, as shown by forum members constantly reminding others about using e-cigarettes in public.
But pictures still appeared earlier this year on citizen journalism website Stomp showing two men smoking e-cigarettes on the bus.
Vapers caught with e-cigarettes in their possession could get into trouble. The Ministry of Health said buying e-cigarettes from overseas websites or bringing them into the country in hand luggage are considered importing, which is illegal.
In a joint statement with HSA and the Health Promotion Board to The Straits Times, the ministry said the law applies even if the product is for personal use.
Under the Tobacco Act, the import, distribution, sale or offer for sale of anything that resembles a tobacco product is prohibited.
Offenders may be fined up to $5,000 for the first time, and up to $10,000 subsequently.
The product has not been proven safe for use, they said, adding that many marketing claims are not supported by evidence. Using it to quit smoking may instead have the "opposite effect" of prolonging addiction to nicotine.
Said the health agencies: "We urge the public to refrain from using e-cigarettes and discard any that they have in possession."
A 41-year-old smoker, whose friend introduced him to the e-cigarette three years ago, claimed the device has helped him to cut down on his costly smoking habit.
But Dr K. Thomas Abraham, an anti-smoking advocate who heads the non-profit Sata CommHealth, said there are other proven methods to quit, like nicotine patches.
"The concern is whether it might lead to more nicotine addiction, especially among youth."