SAN FRANCISCO—A mail scam that was sent to a San Francisco Police Department employee in a priority mail envelope via U.S. Postal Service with a letter inside, has lead the SFPD to announce a warning to the public.

According to an SFPD press release, the letter explained how the recipient was selected to be a mystery shopper. There was also a check inside for several thousands of dollars. The SFPD employee specifically received a check for $2,890. SFPD are warning residents to not cash the check.

The SFPD  has explained that the letter gives instructions on how the program works as it asked the recipient to deposit the money into their bank account and deduct $200 for completing the assignment. The instructions further say to wire $2,690 via Western Union and use $90 for transfer fees.

“The way this works is the recipient deposits the check into their bank account. This fraudulent check will not clear due to insufficient funds. The recipient is then responsible for the amount of the check, meanwhile the money wired earlier will have been successfully transferred,” states the SFPD.

Currently no cases have been reported. The SFPD employee has so far been the only one to receive the scam.

The SFPD is asking anyone who receives this letter to call local police and report the incident online or call US Postal Police Inspectors at 1-877-876-2455.