The police have rounded up 242 people for questioning over their roles in about 600 scams involving more than $7.2 million.
The 149 men and 93 women, believed to be scammers or money mules, have not been formally arrested but are assisting with investigations, the police said yesterday.
The youngest person involved is 15 years old and the oldest, 75, said the police, who brought in the suspects over several operations in the first two weeks of the year.
The schemes being investigated included Internet love scams, e-commerce scams and banking-related phishing scams.
Banking scams have been in the spotlight recently.
At least 469 people were tricked by a text message purportedly from OCBC Bank that linked them to a site that looked like the bank's login page.
They lost $8.5 million in total after keying in their details, effectively handing over their accounts to the scammers.
It is not known if the people rounded up by the police were involved in this particular scam.
Cheating carries a jail term of up to 10 years and a fine.
If convicted of money laundering, a person can be jailed for up to 10 years, fined up to $500,000, or both.
The police warned: "To avoid being an accomplice to crimes, members of the public should always reject requests by others to use their bank accounts or mobile lines, as they will be held accountable if these are linked to crimes."