An inquisitorial system is a legal system in which the court, or a part of the court, is actively involved in investigating the facts of the case. This is distinct from an adversarial system, in which the role of the court is primarily that of an impartial referee between the prosecution and the defense. Inquisitorial systems are used primarily in countries with civil legal systems, such as France and Italy, or legal systems based on Islamic law like Saudi Arabia,Dammer ,Harry R. and Albanese Jay S.; Comparative Criminal Justice Systems, p. 149 rather than in common law systems. It is the prevalent legal system in Continental Europe, Latin America, African countries not formerly under British rule, East Asia (except Hong Kong), Indochina, Thailand, the Philippines, and Indonesia. Most countries with an inquisitorial system also have some form of civil code as their main source of law.
