Aichi Halik & Dion Bisara, Jakarta – The Indonesian Ombudsman asked the central bank and the country's financial regulator on Monday to launch an in-depth investigation into abnormal changes in customer-account balances at state-controlled lender Bank Mandiri.
Some customers were surprised to discover on Saturday morning that their bank balances had been reduced to zero, while others had suddenly become tenfold richer.
Bank Mandiri corporate secretary Rohan Hafas said later on Saturday that the lender had experienced a glitch during a midnight backup process, which affected about 1.5 million accounts, or 10 percent of the total.
The lender worked through the day to fix the problem, which was mostly resolved by the afternoon.
However, the owners of 2,670 accounts that saw increased balances managed to withdraw the funds or transfer it to other accounts. Mandiri is still working to determine which of these actions were on purpose, while the lender tries to recover the funds, Rohan said.
For the Ombudsman, the error was enough to warrant a thorough investigation by the Financial Services Authority (OJK) over concerns that there may have been foul play behind the incident.
Although some people previously reported irregularities in their bank accounts, some of which were reported in the local media, it usually involved a single account. Saturday's incident is in a class of its own in terms of scale.
"It is necessary to immediately establish investigative teams, both inside Bank Mandiri and by the OJK and Bank Indonesia, to see why this incident occurred," Ombudsman member Dadan Suparjo Suharmawijaya said on Monday.
"This incident is beyond the scope of normal maintenance. If there was a migration of customer funds, this certainly must be investigated," he added.
The OJK said in a statement that it already asked Bank Mandiri to immediately report the problems and the steps it will take to prevent similar incidents in future.
"At present, the most important thing is that services have returned to normal and Bank Mandiri has also guaranteed the security of customer funds," the regulator said.
"Banks must have and implement good operational standards; if a system disruption occurs, they should prioritize consumer protection and customers' rights," it added.
The OJK stopped short, however, of saying whether an investigation of Mandiri was imminent.
Onny Widjanarko, executive director of Bank Indonesia's communication department, said the central bank, which also oversees payment systems, was looking into the incident.
"It is currently under investigation and being evaluated for future improvements," Onny told Tempo.
Still, the incident has damaged the reputation of the lender, which until two years ago, was the country's largest bank by assets, before being overtaken by Bank Rakyat Indonesia.
Mandiri's shares declined 1.3 percent on the Indonesia Stock Exchange (IDX) over the past two days, wiping out some of last week's 2.7 percent gains.