The Metropolitan Police Department has arrested a former convenience store employee on suspicion of computer fraud involving the alleged use of customer credit card information.

Daijiro Kamino, 29, of Taito Ward, Tokyo, stole information printed on the credit cards during his part-time job at a FamilyMart in Chofu between February and September last year. He allegedly photographed the cards using a smartphone or wrote down the serial numbers, expiration dates and security codes when customers weren't looking.

Kamino admitted to using the credit card data to obtain ¥176,000 in electronic money issued by a gaming company between September and December last year. Police believe he typed the credit card data into his personal computer.

Kamino, however, is believed to have stolen credit card data from at least 12 customers to purchase some ¥1.2 million in accessories and other items online.

Experts say credit card holders should not take their eyes off their cards when presenting them at stores, and some recommend covering the crucial security codes printed on the back with tape.