Hackers have stolen "significant sums of money'' from businesses on Auckland's North Shore in the past couple of months, police say.
The companies, who regularly order goods from China and have dealt with their suppliers for many years, received emails asking for the usual payment to be made into a different bank account.
When the businesses questioned the suppliers via email to query the change, they received confirmation the details were correct.
"In both cases, the email accounts belonging to the Chinese suppliers have been hacked,'' said Detective Chris Blake, from the North Shore police CIB.
"The confirmation email is also a fraudulent message that has again been sent by hackers who have accessed the Chinese email account.''