Cleveland Police said the elderly victims responded to letters from abroad telling them they had won large amounts of money.

They were told to send cash via a money transfer system in order to receive their winnings.

Each handed over sums between �853 and �3,800, and police are concerned that others may be tempted to do the same.

Bank details

The letters were received from Spain, Canada and Australia.

In the Spanish case, the victim gave out bank details after being told they were needed so the account could be credited.

Det Sgt Ted Butcher said: "Once again, I'd stress that if something seems too good to be true then is probably is.