Bank employees were told 23 out of 144 jobs were set to go from the fraud team from March 28.

A senior bank source told BusinessDay fraud-related writeoffs would rise as a result of job cuts at the team that targets misuse of internet banking, cheques, mortgages, personal loans, car loans and eftpos facilities, including ATM-skimming.

"Fraudsters will be able to get away with a lot more now," the source said. "[ANZ management] said they expect to see more writeoffs but at the moment they have got no idea what the impact is going to be."

The ANZ employee said many investigations would fail to prevent fraud simply because there were not enough employees to meet deadlines for background checks.

"By the time the case is blown out, it is too late to catch the fraud. We wouldn't be able to stop it before it goes out."

Yesterday, ANZ moved to assure customers their accounts would remain secure.

''These changes reflect our continued investment in technology, which means we'll be able to provide the same level of fraud protection without the need for as much manual intervention,'' a bank spokesman said.

''There will be no impact on our customers as we guarantee that if they are the innocent victim of fraud they will be reimbursed for any losses by ANZ.''

Figures released in December by the Australian Payments Clearing Association showed credit card fraud topped $210 million last financial year - a rise of $39 million on the previous year.

There are also concerns about the security of the bank's information following a plan to send jobs to the Philippines from the specialised Falcon unit, which investigates credit card fraud.

ANZ has announced plans to eliminate 130 jobs, and details of discussions between the bank and the Finance Sector Union leaked last week indicate that 700 jobs will go this year from the bank's 49,000-strong workforce.