Wellington, Feb 5 NZPA - ANZ Bank has warned its Australian internet customers not to respond to a fake form that asks for personal details when they log onto the bank's website.

The issue was contained to Australian bank customers and the bank was not aware of any of New Zealand customers being affected, said external communications senior manager Virginia Stracey-Clitherow.

The form appeared after customers using internet banking had successfully logged on.

It was not a legitimate form , should not be filled in, and customers should immediately end their internet banking session, the bank warned.

ANZ would keep a close eye on the situation and would post messages for our internet banking customers if appropriate, Ms Stracey-Clitherow said.

"We urge customers to be extra vigilant when using internet banking over the weekend and if they see anything out of the ordinary to contact their bank as soon as possible."

The bank urged people to take the basic precautions when using internet banking or receiving emails about their accounts.

Concerned ANZ customers can call the internet banking helpdesk on 0800 368 524.