A chief executive who appeared on the Sunday Times Rich List was jailed for a 350 million fraud uncovered after one of his employees hit the wrong button on a fax machine.

Virendra Rastogi spent six years running an "incestuous empire" of fictitious firms whose real premises included a cowshed in India and a launderette in America.

A judge said he caused banks on both sides of the Atlantic "enormous damage" by tricking them into funding non-existent deals in "a crime of the utmost gravity".

Rastogi's metal trading firm, RBG Resources, even duped Jack Cunningham, MP, Lord Holme, Lord Woolmer and Lord Gray to become advisers to give it a veneer of respectability.

The 39-year-old father of two lived a life of luxury at an exclusive Mayfair flat in central London and was chauffeur driven everywhere. He earned 4.15million in just five years, giving him a place on the Rich List as one of Britain's wealthiest Asian businessmen.

But after masterminding a highly sophisticated deceit it was a simple fax error - when a company "flunky" sent the wrong documents from a fake office in Hong Kong - that raised the suspicions of auditors and triggered the operation's downfall.

Investigators from the Serious Fraud Office later swooped on Rastogi's home in 2002 and caught him frantically shredding documents.

After a massive investigation and trial - costing the taxpayer at least 10million - three men were found guilty of an international conspiracy to defraud.

Judge James Wadsworth, QC, jailed Rastogi for nine and a half years at Southwark Crown Court.

He told him: "Your brains made it as large as it became. Over the years the banks were induced by your falsehoods to advance literally billions of dollars of trades that did not exist in any real sense."

Co-conspirators Anand Jain, the "facilitator' of the fraud, was given an eight and a half year sentence and Guantam Majumdar, once a respected banker in the City, was jailed for seven and a half years.

The court heard that Rastogi, helped by his brother in America, set up an "empire of imaginary metal", boasting a corporate address in Piccadilly, central London.

He ran a web of 324 "client companies", which were apparently ordering vast quantities of metal through RBG from the USA, United Arab Emirates, Hong Kong and Singapore.

But the businesses, supposedly with multi-million pound turnovers, were simply "sham" operations in small flats and shops with few assets beyond a table and chair. Investigators were amazed to trace one to a cowshed in India, another a launderette in New Jersey, while a third was the home of an elderly woman who sold scrapbooks.

Each "shell" trader had headed notepaper and company stamps and a complex paper trail of bogus orders, deliveries and accounts was created.

The financial world increasingly saw RBG as a highly successful international metal trader with an annual 1 billion dollar turnover - and it secured huge loans from creditors at major, global financial institutions, such as German-based West LB and General Motors.

Suspicion was averted by systematically clearing loans with even bigger borrowings.

Investigators found that, altogether banks, in America and the UK had been conned into lending several billion dollars, although the "circular movement of monies" meant 343.5 million had actually disappeared. Much of it was laundered through Dubai and Switzerland, with at least 40 million believed to have been sent to India. None of the money has been recovered.

Rastogi convinced the financial world of his credibility by insisting on having internationally renowned firm Pricewaterhouse Cooper as his auditors.

In 2002 a PwC auditor in Romania became suspicious when six documents - purporting to be sent from six different companies all over the world - were all sent from the same fax machine in Hong Kong. PwC resigned in the middle of the annual audit.

As Rastogi and others desperately tried to stave off disaster, workers were ordered into the office for "file tidying" weekends and were issued with "pure theatre" scripts to learn in case new auditors called. But it was too late; the massive charade had finally been exposed and the Piccadilly-based trading giant was branded "rotten to the core".