Australian bank ANZ has had to refund to customers a total of A$45 million following a major credit card processing mistake.

According to reports the leading Australian lender has refunded the multi-million dollar sum after 200,000 MasterCard holders were accidentally charged twice for transactions over a weekend period.

The problem, in which funds were essentially taken twice from cardholder accounts, was limited to non-ANZ account holders who used ANZ eftpos facilities. The error was due to a computer database problem, which did not affect ANZ bank members as their transactions are handled by a different database.

The problem persisted for an extended weekend period, from 9pm on Friday to the end of the working day on the following Monday.

It’s obviously quite embarrassing for us … you expect these processes to occur with zero errors, an ANZ spokesman told The Australian newspaper.

ANZ said it was able to refund the A$45 million in erroneous charges within a day of discovering the problem.