Police have arrested 12 women and a man for their suspected involvement in vice-related activities in residential areas.
The suspects, aged between 23 and 46, were nabbed last month when officers from the Ang Mo Kio Police Division raided five residential units in Kovan, Sembawang and Yishun.
Cash amounting to $1,560, mobile phones and other related documents were seized during the raids.
The 12 women are believed to have advertised sexual services through online websites.
The man is believed to have helped manage the vice activities in one of the residential units.
Investigations will also be carried out against the home owners, police added.
Those found guilty of being the tenant, lessee or occupier in charge of a brothel can be fined up to $10,000 and/or jailed for up to five years.
Any person convicted of receiving earnings from prostitutes can be fined up to $10,000 and/or jailed for up to five years.
Police yesterday stressed that they will spare no effort in clamping down on online vice activities, especially those operating in the heartland.
They also advised home owners to be diligent in ensuring that their tenants do not carry out vice activities in their units.