Fewer young people were caught with contraband cigarettes last year.
There were 518 youngsters below the age of 18 nabbed by the Singapore Customs last year for possessing duty-unpaid cigarettes, down from 728 in 2012.
The number of under-18s caught for smoking, buying or having tobacco products also fell, from 6,607 in 2009 to 5,311 last year.
Possessing contraband cigarettes includes buying, smoking or selling duty-unpaid cigarettes, but the Customs spokesman did not give the breakdown of buyers or sellers caught.
Last year, Customs seized 2.9 million packets of contraband cigarettes and caught 6,400 buyers - up from 1.5 million packs seized and 6,248 buyers nabbed in 2012.
Youngsters caught are counselled by Customs officers, their parents and schools are informed, and they are also sent to the Health Sciences Authority (HSA), which can fine them up to $300 for buying, smoking or possessing tobacco products.
Rising prices and the ongoing clampdown on retailers who sell cigarettes to underaged smokers, have led some students to buy contraband cigarettes which are half the price of the duty-paid ones. Some of them sell to other youngsters too.
Last month, cigarette prices rose after tobacco levies were raised by 10 per cent.
Dr Carol Balhetchet, senior director of youth services at the Singapore Children's Society, said the teen cigarette peddlers usually start off as customers of contraband syndicate peddlers. Over time, they end up as low-level peddlers themselves, selling to their friends and other youngsters.
"Some of them even approach young smokers they don't know outside schools and at places where students hang out to sell their cigarettes," she added.
Social workers said most of the young peddlers are not part of any syndicate but are just out to make some easy money.
A private investigator hired by a major tobacco firm to keep tabs on the contraband situation said that syndicates generally shy away from hiring teens to peddle cigarettes now.
He said students usually buy from small-time peddlers, paying between $4.30 and $5.70 a pack. They then sell each pack to other youngsters for a profit of between $1 and $1.50, and the average teen peddler may sell between 20 and 50 packs a week.
He knew of youngsters who go to Johor Baru to buy legal duty-paid cigarettes - which are sold there at less than half the price here - and smuggle about four packs each into Singapore without paying the tax required.
Mr Mohamad Farid Jaaffar, a social worker at the Ang Mo Kio Family Service Centre, said some youngsters sell cigarettes individually to buyers who cannot afford a whole pack. For example, a teen may buy a pack of 20 cigarettes for $5 - or 25 cents each cigarette - and sell at 50 cents per cigarette.
Mr Farid said: "All the money they make goes back to financing their smoking habit and to buy other things. I don't know of any youth who got rich by selling contraband cigarettes."
Secondary Two schoolboy Alex (not his real name), 14, said he started smoking when he was nine and used to approach strangers and foreign workers to buy cigarettes for him.
His friends introduced him to contraband peddlers, who sell him a pack for $5. He said most of the sellers are adults who move around in the void decks near his Toa Payoh home, but some are older teens he knows.
He said: "Many of my friends also buy contraband cigarettes."
Mr Benjamin Yeo, a social worker at Fei Yue Community Services, said it is an uphill task to get smokers to quit.
He said: "Youths smoke because their friends smoke. Some have tried to quit many times but have failed. As long as they stay in a peer group that smokes, it's very hard to quit as their friends would always offer them cigarettes, and if they don't smoke, they feel they are rejecting their friends. Their friends would also ostracise them."