The customer service team at BNZ has apparently been fielding calls from concerned customers all morning.

BNZ customers are concerned about the safety of their funds after receiving suspicious text notifications from the bank.

Auckland customer Joanna Paul received a text notification this morning that said her "wonderful account" was overdrawn by $10,000.

The problem was, she didn't have an account by that name, but she went immediately online to check anyway.

None of her money had been withdrawn and when she called BNZ, the person on the phone told her they had been fielding similar calls from customers all morning and it was just "spam".

READ MORE: Online scams becoming more sophisticated

"I said to him, this is not spam. You've been hacked and your database has either been stolen or sold and now your customers are being contacted with erroneous, disturbing texts that make one immediately go to one's account," Paul said.

She said it was shocking that customers have not been notified yet and it was as if the bank was "scurrying around" trying to fix the problem before news got out.

"If they've got a list of customers, which is linked to all our accounts, and they have phone numbers and can imitate a BNZ message and they can make you log on immediate to your account, how dangerous is that line drawn in the sand?"

Other customers posted to the bank's Facebook page, asking if they were having problems with their notification system and expressing concerns over their money.

BNZ spokeswoman Nicole O'Brien​ said a system error caused a "small number of customers" to receive "routine text and email alerts for accounts that did not belong to them".

BNZ is still investigating the issue and apologises for the inconvenience, she said.

Netsafe chief executive Martin Cocker said given BNZ has said it was an internal system error, it did not look as if any customers would be harmed.

Normally cyber criminals would send an alert asking for some personal details, but that did not seem like the case here, he said.

Meanwhile, the New Zealand Bankers' Association has been hit by an internal email scam, involving a fake email that was sent by the association's chief executive to a colleague.

The email demanded an urgent payment from the colleague and had "classic whaling hallmarks", including poor spelling and grammar.

It used the name of the association's finance manager and the fact he was on holiday to try to create urgency and authenticity.

The email has prompted chief executive Karen Scott-Howman to issue a public reminder that anyone can be targeted by these scams.

"Cyber criminals have become quite sophisticated, and people could easily fall victim to a whaling or bank email scam if they are not vigilant in making the appropriate checks before acting on an email."

Have you also received texts like this or been affected? Comment below or email us: businessday@fairfaxmedia.co.nz