In a statement today, IRB said income tax refunds are only processed based on taxpayers' information stored in IRB's database.
"The email in question also required taxpayers to input their banking information, attached to fake bank websites based on the taxpayer's respective bank.
"By our estimation, these emails are circulating on the Internet at the moment. We advise all taxpayers to exercise caution and not provide any feedback to any instructions in these emails," it said.
IRB said it has so far received 17 phone calls today from taxpayers enquiring about the authenticity of the emails.