Police said some of the offences related to scammed cards.

"One offence involved the victim selling his vehicle on line and the offender gave some story about his money being held up by a freight company that he had got to deliver the vehicle and if the victim paid a deposit into the freight company's account than his money would be released and the victim would be paid," Hunter Valley police said in a statement.

"The account given was the offender's account that was for a fake company.

"Thankfully the bank picked up on this one and helped stop the elderly victim from losing his money."

Police said that property selling sites were also a hotspot, with some of the incidents relating to people paying for advertised items they never receive before the seller disappears.

"We are seeing these types of frauds on the increase and there may be no warning signs," police said.

Hunter Valley Police District urged traders to check back account transactions regularly and report any suspicious activity.

They also encouraged people to trade face-to-face, check sellers' history and to ignore bargains if they are unsure the transaction will be secure.