According to the DCA's scamwatch operation, scammers from India have been targeting New Zealanders with internet phone calls advising that their computer may be infected and talking them into paying for fake IT security software.
Scamwatch spokesman Jarrod Rendle said that, based on the DCA's research, as many as 30% of adults in New Zealand may have been called and that the fraudsters have generated millions of dollars as a result,
"The message is simple: If someone calls you to say your computer has a virus or problem, it is a scam and you should hang up straight away", he said.
"Tell everyone you know about this scam. Share it with your friends, tweet about it, write a letter to your grandparents. However you do it, spread the word, so New Zealand can, as a country, tell these scammers that we've had enough and we're not falling for their trickery", he added.
Reporting on the media warning, the New Zealand Herald says that the scammer may have scooped up NZ$10 million since the start of the year, when the scam calls started, with around in 20 people called falling the fraud.
The paper cites the case of a Wellington resident Bob Stephens as losing NZ $123 after giving his credit card details to a supposedly Microsoft-related service which emailed and then called him.
He told the paper that, despite his initial scepticism, he was swayed by the slickness of the scam and the supposed association with a known brand.
"The Microsoft part induced me into going further," Stephens said, adding that he admits he is almost computer illiterate, so when he saw them opening up what looked like viruses in my computer "that's the point that I became naive and they became sophisticated."
Stephens says he later cancelled the family's credit cards and spent a further $100 to ensure that his computer was not really infected with harmful software from the fraudsters.
The paper quotes the Need-a-Nerd computer service as saying the scammers are unusually aggressive, especially when rebuffed, and often intimidated people.