POLICE are hunting a "softly spoken Scotsman" who is using a new con known as number-spoofing to trick bank customers into handing over thousands of pounds, it emerged yesterday.

The technique involves interfering with the automatic caller display system on mobile phones so it appears the call is coming from their bank.

The fraudsters can use their own computer and a programme to carry out the con or websites which sell 'fake' number services to disguise where a call is coming from.

An investigation by Radio 4's Money Box programme has uncovered four cases in which a "softly spoken Scotsman" used the trick to con more than £185,000 from the victims.

Trish Evans, from Kent, told how she fell victim to the scam after receiving a phone call one evening from the man, who claimed to be from Santander.

He had her name and address details, told her that her bank accounts had been comprised and claimed she needed to transfer her money into a new bank account.

"I said to him how do I know you are from Santander?" she said. "He said 'have you got your bank card with you' and I said yes.

"He said there is a number on the back which is the helpline or service line...and give me your mobile number, which I did.

"He then rang me on my mobile phone and said look at the number that is showing up on your mobile and it was the same as the number of the back of the Santander debit card.

"So I believed he was from Santander and I carried on."

The fraudster got Evans to transfer a total of £50,000 into the new accounts, following a second phone call the next morning.

After putting the phone down she grew suspicious and when she phoned Santander was told there was no-one of the name the man gave working there.

Police are investigating the con and Evans has since managed to get £27,500 of her money back.

However she has lost £22,500, which Santander says it cannot refund as it was an authorised transaction.

Santander is lobbying phone companies to try to put measures in place to prevent the issue happening.

But experts have warned any moves to try to get telephone companies to block certain calls could be open to legal challenges under international conventions.