People are losing thousands of dollars when they fall victim to Facebook scammers selling non-existent goods online.
Police are seeing more people offering to sell items on Facebook without ever intending to supply the goods.
The sellers use an alias, either by giving a false name or an unregistered company to advertise the goods.
If you think about it, you wouldn't leave hundreds of dollars in your letterbox for someone you have never meet or seen, on a promise they may or may not return some day with your goods.
Often sellers communicate only through Facebook with the buyer, who will then deposit cash or funds into an account without actually speaking to, or confirming the identity of, the person they are giving the money to.
Expensive iPhones or vehicle parts are the most frequent goods advertised and some purchases are worth thousands of dollars.
"Using sites that are not reputable to purchase goods can be risky, especially if you don't first verify the seller's identity," said Senior Constable Darryn Buist, of the Otago Coastal Proactive Safety Team.
"If you think about it, you wouldn't leave hundreds of dollars in your letterbox for someone you have never met or seen, on a promise they may or may not return some day with your goods.
"We recommend buying off reputable businesses such as Trade Me as they offer a greater level of protection, but if you are using a non-reputable site like Facebook, then make sure to confirm their identity before completing the sale.
"You can do this by asking the seller for their cellphone number and ringing them to confirm the purchase, as well as asking their full name.
"If it's a significant amount of money, have a bank cheque made out to their full name as this can only go into their named account and will prove the identity of the seller or their respective account if they scam you.
"If you suspect a seller may not be legitimate, do not complete the purchase and report the matter to your local police station."