The Serious Fraud Office both investigates and prosecutes only fraud cases, selecting those that involve large amounts of money, elicit strong public concern, and have a complexity that requires multidisciplinary expertise in the investigation. The 35 police forces of England and Wales are responsible for investigating criminal conduct within their jurisdictions, including fraud. The Crown Prosecution Service prosecutes the cases investigated by police. The Department of Trade and Industry regulates some companies and conducts criminal investigations that involve the operation of these companies, including any fraudulent conduct by their directors. Her Majesty's Commissioners of Inland Revenue and Her Majesty's Commissioners of Customs and Excise investigate and prosecute the evasion of taxes or excise duties. The Financial Services Authority regulates most of the markets and organizations within the financial services sector. This includes the ability to investigate and prosecute possible criminal conduct. The Assets Recovery Agency is instrumental in depriving criminals of the proceeds from their crimes. The procedures used to investigate fraud in the United Kingdom depend on which agency conducts the investigation. Each agency has certain powers and limitations that determine how investigations and prosecutions are handled. The powers and parameters of the various agencies that might become involved in fraud cases are described in this report. The concluding section of the report provides a detailed description of how the Serious Fraud Office conducts fraud investigations, since its exclusive focus on fraud cases has enabled it to develop innovative and technologically sophisticated techniques for such investigations.