ANZ says overseas fraudsters who tampered with some of its cash machines have attempted to steal money from people's bank accounts for a second time.
Some money has been taken from a small number of accounts and transferred to bank accounts in Bulgaria after people used the ATMs in Auckland.
ANZ won't say how many people have been affected or how much has been taken, but will say the fraudsters tried again to take money from accounts on Thursday night.
The bank says blocks were in place to prevent more money being stolen.
KiwiBank says some of its customers who used the tampered ATMs may be affected and its fraud team is investigating.
ASB Bank says it has added safeguards to protect customers whose cards may be at risk, but those who detect any abnormal activity should advise the bank.