Taxpayers are being warned not to fall for hoax phone calls from fraudsters telling them they are eligible for unclaimed money or a tax refund.
Inland Revenue said scammers had been making phone calls to customers using its brand and trying to trick them into paying money.
"Those making thecalls may offer a person a tax refund, a grant, or even unclaimed money if they make an upfront direct payment to a bank account via Western Union," said IRD spokesperson Eleanor Young.
"There have also been cases when a person has been asked to make the transfer online through a website address while they are still talking on the phone."
Young said the fraudsters had also been attempting to get hold of details such as credit card and bank account details.
Anyone who received a suspicious call should hang up immediately, she said.
"If anyone has replied to those behind these scams, and given money or their personal details, they should contact their bank or credit card provider immediately."
People also needed to be aware of email scams, or 'phishing', where an email was fraudulently made to look like it came from Inland Revenue or a tax refund agency.
