SINGAPORE - More than $96,000 in fraudulent credit card transactions were found after police nabbed four syndicate suspects.

Police arrested three men and a woman, aged between 24 and 32, after receiving a report on Feb 1 about fraudulent activities being carried out on YouTrip.

YouTrip is a multi-currency electronic wallet application.

Preliminary investigations revealed that at least 85 fraudulent credit card top-up transactions by 18 suspicious account users were carried out between December 2018 and last month.

In a Tuesday night (Feb 12) statement, police said the transactions amounted to more than $96,000.

Officers from the Commercial Affairs Department identified and arrested the suspects on Monday and Tuesday, and hauled up another 15 for investigations.

Several YouTrip Mastercards, ATM withdrawal receipts, and 12 cellphones were seized, police said.

The four caught are expected to be charged on Wednesday with unauthorised access to computer material under the Computer Misuse and Cybersecurity Act.

Those found guilty can be fined up to $5,000, jailed for up to two years, or both.

Police advised the public to use SMS one-time password (OTP) verifications and notifications for any card purchases to prevent unauthorised use of debit or credit cards.

They also advised against giving out card details to strangers.

"Check bank statements and alert the bank immediately should there be any discrepancies or fraudulent charges," the police added.

YouTrip said in a statement on Thursday that it rolled out a security update last week that requires users to key in a OTP when adding a new credit or debit card for the first time in the app.

The OTP verification code will be sent by the credit card issuing bank via SMS.

YouTrip said that this move will further eliminate cases of fraudulent use, such as top-ups on YouTrip accounts using stolen credit or debit cards.

From last December to January, YouTrip’s fraud monitoring system flagged two signals of suspicious transactions, the statement said.

These signals were a high top-up amount followed by immediate purchases or cash withdrawals to deplete the account balance, and a high frequency of failed top-ups with incorrect credit or debit card credentials.

YouTrip is developed by EZ-Link in partnership with Mastercard and Hong Kong-based mobile payments startup You Technologies Group.

You Technologies Group’s country manager for Singapore Kelvin Lam said: “Fraud prevention and security will continue to be YouTrip’s core mission to our users.

“We will continue to work closely with the authorities and community to ensure a secure and seamless payment experience for all YouTrip users.”

On the recent fraudulent transactions, YouTrip reassured users that the suspicious activities have been contained to the current identified suspects and that users can continue to use the app normally.

Those who detect any suspicious activities in their accounts can contact the customer support team at customer@you.co.