Police guards have been stationed at Commonwealth Bank ATMs after a system outage at the bank disrupted online banking, mobile and telephone transactions and caused some cash machines to spit out large amounts of cash to customers with no funds.
The outage at CBA followed 'routine' overnight database maintenance', which left customers unable to transfer money or pay bills via the bank's online and phone banking services.
Within hours, New South Wales Police received reports of cash being dispensed in large amounts by "a major bank's ATMs", as crowds gathered at up to 40 machines in Melbourne, Sydney and Brisbane.
With the ATMs running in offline mode, CBA customers quickly discovered that they could withdraw large sums of cash, irrespective of their current account balance.
Detective Superintendent Col Dyson, commander of the State Crime Command's Fraud Squad, warned that it is a criminal offence to keep excess money dispensed from an ATM.
"People should realise that even though an ATM has dispensed cash, they are not entitled to that money and are committing a criminal offence if they keep it."
The police moved to place guards at malfunctioning machines while liaising with the bank.
The service disruptions for CBA customers continued throughout the day, with the bank directing clients to bank branches for urgent money transfers. The problem was finally resolved after close of business, and all outstanding scheduled payments processed.
The bank, which is in the middle of a $1.1 billion core banking system upgrade, has suffered a number of outage over the past year. In August, CBA apologised to customers after scheduled system and security upgrades to its NetBank online service disrupted its nationwide payment network. Similar problems caused by a "late running overnight file" affected some of CBA's NetBank and CommBiz customers as well as ATMs in December.