SINGAPORE - A 46-year-old Malaysian man was on Thursday (March 29) sentenced to six months' jail for his role in a thwarted debit card scam involving an $800,000 diamond ring.

The court heard that Tuah Koo Tong, who was found guilty on one count of abetting in the cheating case, had agreed to assist Nyanapragasam V T George, 56, in his scheme.

George, who was sentenced to seven months' jail earlier, had hatched a plan to cheat retail shops using several debit cards he carried.

Unlike credit cards, customers using debit cards need to ensure they have sufficient funds in their account to offset a purchase.

George, also a Malaysian national, knew even with a fake approval code, a charge slip would still be generated by the terminals in the store in the event of a manual or offline debit card transaction.

This would fool the retailer into thinking he has enough money in his account and that the transaction was approved by the customer's bank.

George then recruited Tuah through a friend and promised him a 10 per cent cut.

Tuah's role was to work with one Damayanti to find a store that sells diamonds. On Oct 4 last year, Tuah, George and Damayanti met at Lucky Plaza.

Tuah waited outside Moriya Diamond Boutique as the other two went inside. George then tried to purchase an $800,000 diamond ring using a debit card from the Indian bank ICICI bearing the name Mohamed Ayes. Court documents did not explain how George got the card.

He was hoping to take advantage of the salesman's unfamiliarity with the correct procedure for offline transactions.

For such transactions, the store would need to seek authorisation from both its own and the customer's bank. An approval code would then be generated.

But the salesman at Moriya Diamond Boutique decided to call the store's bank, UOB. A staff there told him that George might be plotting a scam and sent over the bank's fraud investigators.

When they arrived at the store later, they discovered that George had only around S$302 on the debit card.

They reported the incident to the police and George and Tuah were arrested. Tuah, who has been in remand for over five months, was sentenced to six months' jail.

Details about Damayanti were not provided in court documents.