The purpose of this thesis is to identify deficiencies within our system for tracing assets lost as a result of fraud in an international environment and to suggest methods by which they might be remedied. Fraud provides its central theme for several reasons. First, the subject has given rise to a plethora of academic and judicial comment in recent years, whilst generating few universally accepted proposals for improvement or reform. Second, the methods of committing fraud and moving fraudulently obtained assets have recently undergone a sea change, largely as a result of technological, economic and political developments which have reduced the importance of national and geographical borders. Finally, fraud is capable of providing a practical context in which theoretical legal issues, exemplified by the methodologies of tracing and the wider subject of restitution/unjust enrichment, can be examined. As part of this process, this research considers fraud in a practical and theoretical context, and the changing influences upon it, before investigating how it relates to other areas of law. This is done with the specific intention of determining the practical and theoretical goals to which a system for recovering assets lost to fraud should aspire. It then considers the extent to which our present domestic system for tracing assets adequately meets these challenges. These elements are then placed in the wider context of restitution/unjust enrichment in order to consider the extent to which that developing area of law adequately explains tracing and provides a methodology for its fihure development. Finally, the research attempts to place these issues into an international context by examining the principles it has identified from a conflict of laws perspective. The central conclusion of this thesis is that cross-border asset tracing is an intrinsically complex procedure which, as a result of changing political, economic and technological factors is set to become more problematic in the near friture. As a result it is argued that if our system is to remain effective, it must respond to changing circumstances by reference to a logical set of restitutionaiy principles. In this context the difficulties associated with such an approach are assessed and possible options for development and reform are suggested.