A teenager has been arrested after police disrupted a "sophisticated smishing scam" using technology never seen in New Zealand before.
In a statement, police said the Department of Internal Affairs was made aware of the scam in July.
Multiple agencies, including Australia's cybercrime team, soon launched Operation Orca.
Police described smishing - a form of phishing - as when a device known as an SMS Blaster is used as a fake cell tower and tricks nearby cellphones to connect to its fraudulent network.
The SMS Blaster can then send texts claiming to be from banks to try get people to share their personal information like passwords and credit card details.
Detective Superintendent Greg Williams said this was the first case ever of such a device being used in New Zealand.
"By working together we have been able to counter this technology, locate the alleged offender and prevent what could have been large-scale financial losses for many New Zealanders.
"The device in question is believed to have sent thousands of scam text messages, including around 700 in one night.
"The text claimed the recipient's bank account was being checked for fraudulent funds and urged them to click a verification link."
Williams said about 120 people are known to have been affected by this scam but no one has lost any money.
"Cyber-enabled scams are becoming increasingly prevalent, with unscrupulous fraudsters stopping at nothing in their attempts to swindle innocent people out of their hard-earned money," he said.
"NZ Police recognise the life-changing impact of financial crime and will continue to work closely with partner agencies and private industries to keep New Zealanders safe."
Banks said they were continuing to monitor customer transactions in real-time to minimise risk.
The 19-year-old has been charged with interfering with a computer system and would reappear in the Auckland District Court on December 10.
