Fraudsters are using publicly available online information in a series of scam letters posted to Kiwis.
An Auckland business owner, who wanted to be referred to only as Chris, received a phishing scam letter late last month from a "Mr Thomas Nkosi" from South Africa.
The scam used personal details obtained from the Companies Office website and had South African stamps on the envelope.
Chris told the Weekend Herald he was very shocked to receive the letter at home and via post.
"I opened it and was just really surprised. Really surprised that they would actually get my name and address and then send this through.
"It freaked me out a little bit to begin with. I thought 'okay, what do they know about me'. That was my main concern."
The letter asked him to help invest US$12 million ($18 million) in New Zealand in exchange for 25 per cent of the money.
It asked for his "urgent and confidential response" and for his full information including a private mobile phone number and an email address. He contacted the Companies Office, but was told there was nothing they could do to stop people using publicly available information.
"I just figured I'd let people know that this is going on so they don't freak out completely when they get these letters."
A spokeswoman for the Ministry of Business, Innovation and Employment said it was unfortunate the information on the companies register had been used for scamming purposes.
It freaked me out a little bit to begin with. I thought 'okay, what do they know about me'.
"We encourage business owners to be wary of any requests for sensitive information and report any incidents to Scamwatch. We report data collected from Scamwatch to Netsafe."
Martin Cocker, executive director of Netsafe, said the postal scam was concerning, as many people were more susceptible to items received in the post.
"People know there are a number of email scams, but tend to be more trusting of physical items that appear in the mailbox.
"Once the victim is drawn in, the scams often move online because it's more cost-effective for the scammers."
He says there is also a common lottery scam where people are mailed the winning ticket and then have to pay a sum to claim the prize, "which of course they never receive".
Cocker said Netsafe were aware that a number of public sources of information get targeted and used in this way.
"They're making information available as per their legislation and that information is then taken and utilised to create a scam," he said.
"The key thing is that consumers and business owners in this case are aware of what information is public."
A spokeswoman for New Zealand Post says they receive reports from time to time of scam letters sent by post.
"Our advice to people is to be alert to the tell-tale signs of scams which include unsolicited requests for money or personal details."