People in South Holland and The Deepings are being warned about a scam where fraudsters claim to be working for Royal Mail.
Emails from the fraudsters inform people that a parcel is being held for them, but they contain a computer virus that may escape when the person tries to fill in an attached document.
There are no reports yet of anyone in the area opening such emails but Lincolnshire Police, in partnership with the Royal Mail and National Fraud Intelligence Bureau, are advising people not to open the attachment.
A Lincolnshire Police spokesman said: “A scam email with the subject header ‘Mail - Lost/Missing Package’ is currently being sent to people fraudently claiming to be from the Royal Mail.
“The email reads ‘Royal Mail have detained your package for some reason such as lack of a proper invoice or a possible trademark violation and the RM International Mail Branch holding it will notify you of the reason for detention (in writing) and how you can get it released.’
“The email then asks the recipient to open up an attachment to complete a document, but it is believed that the attachment contains a zip file with a malicious virus.
“Royal Mail is aware of the scam and is taking action to protect customer from these fraudsters.”
The spokesman added that Royal Mail is advising people that it never send emails asking for personal or confidential information or with attachments unless asked for by the customer.
Anyone with information should call Action Fraud on 0300 123 2040.