The Serious Fraud Office has begun an investigation into allegations of corruption in the award of multi-million pound oil contracts in the Middle East. A Monaco based company, Unaoil, denies that it helped British and other companies win contracts by corrupting politicians and government officials. The investigation follows a leak of thousands of emails and other documents. Jane Deith has been given access to the leaked papers and reveals what they tell us about the business of oil. Reporter: Jane Deith Producer: Paul Grant.