stated in the original research it is important to acknowledge that mapping approaches across Europe can be problematic due to language barriers, which can affect literature searches and reviews. Furthermore, in some jurisdictions there are multiple police services/forces. Information therefore focuses on those mechanisms deemed to represent external, independent oversight, but also includes attendant support mechanisms in operation across a range of models and levels of independence. The information presented provides answers as to the legal basis for the establishment and functioning of the oversight body; the purpose, jurisdiction and scope of work of the body; the model applied by the body; the level/type of powers of investigation held by body; the structure of the body; and the resources attributed to the body. Furthermore, where there has been no change in oversight since 2015, when information has been unobtainable, or where oversight bodies do not represent an external element nor independence this is made clear. In some cases more than one method of oversight operates in a single member country. In these cases mechanisms, which demonstrate external oversight and independence are presented alongside additional bodies, which may exhibit lesser traits of external oversight and independence. 14