"And that's just the people reporting it to us," Ms Chisholm said. "It's right across the country, from the Far North to the far south.
"If anybody cold calls you saying you've got a computer virus and it's urgent, then just hang up.
"They will engage you and eventually either put malware (software designed to disrupt or damage a computer) in your computer so they can go back in later and basically clone your data, or ask you to give credit card details to pay for the five years' worth of anti-virus they say they've installed. They haven't - it's a scam."
She said the callers would become increasingly aggressive and were very convincing, ringing up and saying they were from a reputable company, such as Spark, Telecom, Vodafone or Microsoft, trying to fool people into believing they had a virus on their computers.
Companies would never ring up and ask for access to computers or for credit card details.
In each Kerikeri case, the victim had been cold-called by someone claiming to be from Spark (formerly Telecom) making inquiries about supposed internet or email problems. The victims gave information to the callers which allowed their computers and email systems to be remotely accessed. As a result, the victims had been defrauded of substantial sums of money.
"These people come across as credible, quoting reference numbers and sounding professional. Nonetheless, they are defrauding people," Mr Robinson said.
Police are investigating. The national cybercrime unit may also become involved.
Mr Robinson urged Northlanders never to give out information - particularly passwords, access codes or PIN numbers - if someone called up inquiring about internet, email or banking. The victims were working with their banks in the hope of recovering the missing money. However, in general banks would not reimburse customers who had disclosed their passwords. To report scams to NetSafe go to theorb.org.nz or ring 0508 NETSAFE.