Suspected unlicensed tourist guides can be detained, questioned and even fined on the spot by enforcement officers, under proposed changes to the law.
Those who do not cooperate with the officers can even be hauled to the police station for further investigations.
Offenders may also face harsher penalties, with plans to double the maximum fine to $10,000 for recalcitrants.
The proposals come after a year-long review by the Ministry of Trade and Industry and the Singapore Tourism Board (STB) to tackle the growing menace amid surging tourist arrivals.
Those who do not play by the rules are often foreigners accompanying tour groups from overseas. Others may be work-pass holders who take on freelance guiding jobs without the requisite licence.
They frequently give wrong information to tourists and take away business from the 2,315 licensed guides here.
The ministry said in a statement on Friday that the proposed changes are part of the Government's ongoing efforts to raise the quality of tourist guides.
Second Minister for Trade and Industry S. Iswaran said they are "a key touch-point for many tourists" and are important in promoting Singapore.
He added that standards have to be improved and tougher action taken against illegal guides who could "otherwise tarnish Singapore's image and impede the professional development of the tourist guide industry".
Besides the proposed harsher penalties, STB also plans to improve the standards of guides here. It will roll out guidelines to better train licensed guides and raise their professionalism.