The tourists, aged between 31 and 71, were separately found bringing cash amounting to between S$24,000 and S$109,000 into Singapore without declaration during a week-long crackdown campaign between June 17 and 23, Channel News Asia reported.
The Corruption, Drug Trafficking and Other Serious Crimes Act limits the amount a person can carry undeclared into the country to S$20,000.
Travelers are required to submit a declaration 72 hours before entering or leaving the country.
Violations entail jail terms of up to three years, a fine of up to S$50,000 or both.
During the campaign, more than 10,000 travelers were stopped for checks and more than 18,000 pieces of luggage were scanned or searched at the airport’s four terminals, The Straits Times reported, citing a source from the Immigration and Checkpoints Authority.