ANZ customers have been unable to access internet banking today due to an issue in the bank's communications network.
ANZ said its customers have not been able to use internet banking and have had limited access to their funds via ATMs or EFTPOS since about 9am.
The bank has approximately 1.8 million active internet-banking customers.
Call centre and branch staff have also been affected by the problem.
As of about 10:45am, services had been restored, according to the bank. ANZ is looking into the root cause of the problem.
The problem followed an outage last week, reported by the Australian Financial Review. The bank's internet banking and call centre facilities were out of order for much of a day, which the bank blamed on a faulty mainframe disk drive at one of its Melbourne datacentres.
"Last week's problem was to do with a faulty disk. So this appears to be unrelated," the bank said in a statement. "We're not happy to have had two problems in two weeks. We apologise to our customers for the inconvenience."