Definition of Serious Fraud Office
The Serious Fraud Office (SFO) is an independent UK government agency that is responsible for investigating and prosecuting serious crimes involving financial wrongdoing and complex economic crimes, such as the Libor manipulation.
The agency is part of the UK criminal justice system with jurisdiction in England, Wales and Northern Ireland only.
The SFO has suffered a series of reversals in 2012, including the collapse of an investigation against property tycoons and brothers Robert and Vincent Tchenguiz. 
Evidence from this case has raised some concerns about the SFO’s competence in pursuing complex financial crimes. The SFO had sought search warrants against the brothers over their suspected role in the collapse of Kaupthing, the failed Icelandic bank. 
The warrants were ruled unlawful, and the presiding judges called for more funding for the financial watchdog, which has seen its budget cut from £52m in 2008 to £32m in 2012. 
However, in 2012, the SFO worked on the successful conviction of Asil Nadir on charges of theft from a public company. Mr Nadir is the former chairman and chief executive of Polly Peck - the a multinational conglomerate covering electronics, textiles, food, leisure and the Del Monte fruit group.
In August of that year, he was found guilty by a jury of stealing £29m from the company and it collapsed in 1990.
The SFO’s Tchenguiz case
Man from Del Monte found guilty
Tchenguiz lawyers criticise SFO
Tchenguiz warrants ruled unlawful
SFO seeks to reclaim some of Nadir costs
Asil Nadir guilty of £29m Polly Peck theft
Finance and fraud: Serious shortcomings