Tough action by the police may have driven more of the sex trade online.
In 2005, 3,200 freelance sex workers were rounded up, according to the police.
In 2009, that figure jumped to 7,600.
New ads promoting sex-for-hire websites have sprung up despite the police raid at a Bukit Panjang condominium that forced an online prostitution ring to shut down.
The arrest of 11 men and 12 women last Wednesday has not deterred these online sex peddlers.
Their brazen ads are on the very same sex forum that the busted ring advertised in, displaying choices, prices and Singapore mobile phone numbers.
Our correspondent Zaihan Mohamed Yusof speaks to insiders familiar with sex syndicates to find out their modus operandi.