Police are urging New Zealanders to be vigilant after scammers claiming to be government staff are calling to demand money and making threats to victims.
In recent events, callers demanded money in the form of vouchers and made "concerning threats to victims should they not transfer funds".
Police said these scammers appeared "fairly legitimate" if they knew the person's name and telephone number.
However, they assured the public threatening behaviour would not be made from government staff.
New Zealand police chief information security officer Paul Blowers said it was "relatively easy" for any scammer to find personal details.
"A simple white book query, checking social media online, or by social engineering means, such as convincing a friend of a friend to reveal some details.
"Police are not able to track these callers directly but depending on how they have configured their mobile phone, some details can be revealed."
He said to track callers, it would require closer interactions with the phone service providers and a special warrant was likely needed.
When receiving a call demanding a payment:
• Seek validation of who the caller actually is. Always ask for a full name and the company or agency details.
• Validate the phone number of the caller and ask that they call you from a landline if they are using a mobile phone.
• Ignore calls from unknown mobile numbers.
• Don't share your personal details until you are convinced the caller is legitimate.
• If you are threatened, simply hang up - the IRD or any other government agency, Police or a crown entity will not threaten someone.
• Don't trust anyone who calls you and asks for your financial-related information such as your account details and passwords - again simply hang up, call them on their published contact 0800 number or arrange a meeting at the relevant agency branch.
• When you do receive a call resulting in any threatening remarks, report it to either Scamwatch, Department of Internal Affairs (Anti-Spam), NetSafe or Connect Smart. Contact NZ Police if criminal activity is evident.