The warning comes after an older woman in the city wired $250,000 out of the country after she was convinced through a series of phone calls and emails that her grandson was being held in a foreign prison and needed the money.
"The scammers were able to deceive the victim through an elaborate series of phone calls and lies, resulting in over $250,000 being wired to a bank in Peru," Chesterfield police said in a statement.
The St. Louis Post-Dispatch reported that the woman reported the scam to police on Monday. The bank had stepped in an stopped a final transaction and warned her, but several money transfers had already occurred.
"Scams of this nature are quite common and the Chesterfield Police Department warns residents to verify any circumstance wherein they may be contacted and asked to send money to another country," police said. "It is unknown how this victim was identified as a target."
Police said they know of no other similar cases in the city.
The newspaper quoted Chesterfield police spokesman Capt. Steve Lewis, who said these kind of scams are on the rise.
"I think people are contacted somewhere in the St. Louis area probably on a daily basis," he told the Post-Dispatch. "There are a lot of scams, so many variances of the scam, but they typically are not to this degree, (involving) this amount of money."