The PSNI is telling people to be on the lookout for an email that aims to steal their credit card number and other online credentials.
The warning applies to all of Northern Ireland and was issued by the PSNI on Tuesday morning.
The apparent aim of the scam is to get unknowing Internet users to click on a link contained in an email.
Once clicked on, the link can lead to criminals collating information, such as a credit card numbers, and using them to commit crime.
"Received this email and think you have been called as a witness," said the PSNI on social media.
"In true panto style ... oh no you haven't! Remember take five and don't click on the link. Curiosity might just lead to malware or the loss of your online credentials."
If you think you have been the victim of a fraud, visit How to report a fraud on the PSNI website.