New Zealand Police is reminding people to be alert to fraudulent activity and to take particular care when selling goods through social media platforms and online websites.

"If you plan to sell your unwanted items, make sure you take care when doing so," says Police Tactical Crime Unit Detective Sergeant Carl Newton.

There has been a notable increase in people handing over property to people posing as buyers after being falsely led to believe that they've been paid for the item.

In such cases, it is common for the claimed buyer to show proof of payment in the form of a cell phone screenshot of a bank transfer of fund to the sellers.

However, the money is never actually deposited into the seller's account despite the claimed buyer appearing honest and genuine.

These type of fraudulent purchases occur with lower value items but also happen with more expensive things such as the sale of motor vehicles.

"Whenever selling goods, make sure you deal in cash or ensure the money has been actually received in your bank before handing the item over," says Detective Sergeant Carl Newton.

It is easy for someone to claim a bank transfer has been made by showing a false record of a deposit, only for the seller to find out later on that the item hasn't been paid for.

"If you can't see the money in your bank account, treat it as not being in there and retain the goods."

In addition to taking appropriate steps to ensure the money is actually received before handing over sold items, Police recommend not conducting these sales at the seller's address or inviting someone into your own address. Police recommend a safe trading zone and some additional advice is below:

Police tips

• Meet in a public, well-lit area or consider only trading in daylight hours.
• Trade near, or in front of, a known/working CCTV camera, in busy foot-traffic or perhaps by a Police station.
• Don't go to the transaction alone.
• Make sure a friend or family member is aware of the transaction meet-up
• Be extra cautious when buying or selling valuable items such as vehicles and jewellery.
• Trust your instincts, if it sounds like a scam, it probably is.
• If somebody is not willing to come to a safe trade zone, it is probably not a legitimate transaction.

Call 111 in an emergency.

"We would rather attend to prevent a crime happening, than attend after an offence has occurred," says Detective Sergeant Carl Newton.

"If it's already happened you can provide information via 105.police.govt.nz, call Police on 105, or report anonymously via Crime Stoppers on 0800 555 111."