Dartmouth police are asking residents to remain vigilant of possible scams after a resident received an extortion letter in the mail.

Police shared a copy of the four-page printed letter on its Facebook page. The letter was addressed to a North Dartmouth resident who is not being identified, but postmarked to a South Dartmouth ZIP code.

The letter, written by an individual calling themselves "BlackBat~19," states that the author has collected evidence of a "secret you are keeping from your wife and everyone else."

The letter author claims to have stumbled on an alleged misadventure working a job in "N Dartmouth" and demands $8,150 in exchange to keep quiet.

The letter does not specify the alleged misdeed, but demands the recipient to pay the $8,150 ransom within nine days of postmark in Bitcoin, a digital currency.

The letter includes several pages of steps guiding the recipient through acquiring Bitcoin and transferring them online.

Dartmouth police are asking any residents who receive a similar letter to alert them or their local police department to the issue.