Nine people have been charged with dishonesty offences in relation to dozens of reports of scams involving buying cars on Facebook marketplace.
Police have received more than 50 reports in the past 12 months from car owners who were scammed after listing their cars on the platform.
In these scams, the purchaser would pay the owner by cheque and the funds would show as "pending" in the seller's bank account.
The cheques were then dishonoured or reversed due to insufficient funds three to six days later. The scammer has by then typically sold the vehicle on to another member fo the public and can no longer be contacted.
Detective Senior Sergeant Callum McNeill said police wanted the public to be wary of the risks of selling vehicles on unregulated websites such as Facebook marketplace.
"Police have noticed a significant increase in reports from victims in these scams in the past year and we take these matters seriously," McNeill said.
"We want the community to be cautious when accepting payments by cheques. You should not hand over possession of your vehicle until the payment has been cleared and is no longer showing as pending in your bank account.
"We would also recommend that people selling vehicles online use regulated marketplace websites such as Trade Me."
Anyone who has been a victim of this scam was asked to make a report to the police.