Southern police are calling for people to vigilant after a "significant increase'' in people using Facebook to rip-off unsuspecting consumers.
Senior Constable Darryn Buist, of the Otago Coastal Proactive Safety Team, said people were being scammed by users who advertised sometimes expensive items through Facebook with no intention of supplying the goods to the purchaser.
The sellers used an alias, either by giving a false name or an unregistered company to advertise the goods, Buist said.
Often sellers communicated only through Facebook with the buyer, who was then asked to deposit cash or funds into an account without actually speaking to, or confirming the identity of, the person they were giving the money to.
Expensive iPhones or vehicle parts were the most frequent goods advertised and some purchases had been worth thousands of dollars, he said.