NORTH Yorkshire trading standards office has warned farmers and other business people to be on their guard and ignore any invitation to invest in a fraudulent scheme to send money to Nigeria.

This elaborate scam has already cost many business people up to £310,000 each in what is thought to be a £35m fraud, and one local farmer has already been approached.

The conmen send out a letter inviting the recipient to help in transferring tens of millions of dollars in overdue contract payments to a foreign bank account, namely their own, or their company's.

For this help, the sender promises to pay 20 per cent of the value of the transaction, amounting to several million dollars, to the individual.

After an exchange of letters and bank details, the target is then asked to make a payment to cover the cost of lawyers' fees.

This is likely to be the last contact the victim will have - and their money will disappear forever.

Mr Allen Duffeld, who farms near Thirsk, was offered $6.2m in return for letting $31m in overdue contract payments to the former military rulers of Nigeria be paid into his bank account. But he was among the majority of people who did not fall for the scam.

He said that even though farming was going through a rough time, he, like many others, had been brought up to earn an honest living.

"I am not the idiot that the sender is expecting and I know that in this world you only get what you work for," he said.

A spokesman for trading standards said its office was aware of the scam and that police were investigating. He said: "We would advise anyone approached in this way not to give their bank account details to people they do not know.