North Wales Police Community Alerts has issued a warning about online fraud.
It says: "Since the 1st of January 2023 North Wales Police have received 21 reports of victims selling items online and not receiving payment, totalling a loss of over £10,600.
"Criminals are using a number of methods and are targeting those selling high value items such as mobile phones, tablets and laptops.
"In some cases, the victims receive a fake email from Paypal claiming the payment has been made and the victim is then urged to send the sold item to the suspect in the post, only to find that no monies have actually been paid and all contact with the buyer is blocked.
"In other cases, suspects have attended the victims home address and pretended to make payment using a fake banking app or using forged bank notes to pay before leaving with the goods.
"Anyone selling items online are urged to ensure that payment is made in full prior to parting with any goods. If using Paypal, check the payment has been made using the app and do not agree to use the Friends and Family option as there is no protection offered with this service."