A 70-year-old Burke-area woman answered her phone this week and was told she’d won $3.5 million and a brand-new Mercedes, reported Fairfax County Police.

But there was a catch. The woman was instructed to purchase Green Dot payment cards, and provide the caller with the account numbers.

Police said the woman purchased $13,000 of the Green Dot cards and provided the numbers to the male caller, along with her social security number, date of birth and other private information, as she was instructed.

Green Dot cards are pre-paid, loadable cards similar to other brands of credit and debit cards. Detectives caution these scams are not isolated to any particular financial institution.

By the time a relative discovered what had happened, it was too late and the victim lost much of her money.

Fairfax County Police said this is another in a series of scams Financial Crimes Unit detectives are seeing across the region. They warn, as with many of these scams, once money is wired or sent away, there is very little that can be done to recover the funds.

Detectives are working to educate the public about these types of schemes and ruses.

To learn more, or to report an incident, visit Financial Crime Online Reporting. Since the page went live in October 2011, more than 1,200 crimes have been reported.