Regulating migration is still perceived as a reserved domain of national states under International Law. It falls under the sovereign rights of a state to decide which policy to adopt towards illegal migration within the framework of Human Rights Law. So, how does an entity can come to finance a related migration project outside its given territory? This book aims at answering this question, focusing on a specific project, by giving a full picture of the legal framework it involves. The project in focus is an European Union twinning project: "Support to Turkey''s Capacity in Combating Illegal Migration and Establishment of Removal Centers for Illegal Migrants" which started in 2007 and will end in 2012. It involves an institution, the European Union, where members perceive migration as a hot itemi and an EU candidate which is a key migration platform between two continents, Turkey. By those characteristics, the project cannot be disregarded. Furthermore this work concerns a sensitive question ignored by most states: the detention of irregular migrants.