This thesis deals with “country of origin information” (or COI), a type of expert knowledge and a field of professional practices that has emerged since the late 1980s in the framework of West European and North American asylum administrations in order to support refugee status determination. This information is used to evaluate the credibility of asylum seekers and to assess their eligibility to international protection. Rather than focusing on this instrumental role of COI in asylum procedures, this research explores the norms and values that govern the works of COI units in several European asylum administrations. It also analyses the legitimation work involved in the production of COI, with reference to knowledge production, bureaucratic practices and state authority. The format of the thesis is a PhD by published work comprising three articles. This collection of articles is eclectic both from a disciplinary and methodological perspective. Published respectively in history, political science and social anthropology journals, the three articles are integrated in an accompanying text, which offers a common contextual, thematic and theoretical introduction, as well as a methodological discussion and an articulation of the main results of the thesis. The first article – the “history article” – adopts a diachronic approach and analyses the creation and development of the French COI unit within the Office français de protection des réfugiés et des apatrides, Ofpra. Based primarily on archival data collected at the French asylum administration, it examines the institutionalisation of the “documentation” on countries of origin in the French asylum administration between 1988 and 2008 and shows how this history reflects that of the bureaucratisation of asylum procedures. It also uncovers the role and dynamics of formal and informal cooperation with European COI units in the vertical and horizontal processes of Europeanisation of asylum policies. The second article – the “distance article” – looks at the separation between COI production and its utilisation in assessing asylum applications. Looking at the case of the Norwegian COI unit, the article shows how this separation is materialised through an “infrastructure of distantiation” built around COI production sites. This apparatus is discernible not only in discourses and practices, but also in the organisational structures, spaces, and legal norms that contribute to the ecology of this specific site of expert knowledge production. The production of distance participates in the construction of the legitimacy of both institutions and individual actors involved in knowledge production. The third article – the “access article” – examines the unsuccessful negotiation for access to conduct ethnographic research with the Swiss and Norwegian COI units. The article reveals how the intended research competed with the heads of both units’ beliefs and identities, questioning their emic “idealised construction” of COI as both a type of knowledge and a field of practice. The negotiation of access became a competition over cognitive authority and the monopoly of legitimate knowledge production about the COI field. Taken together, the three article demonstrate that the field of COI is saturated with the question of the (self-)representation of the state and of the bureaucratic actors that embody it. The articles also offer an entry into the dynamics of the construction of legibility and illegibility in asylum bureaucracies and illustrate how the situated nature of expertise is negotiated by COI units. By looking at the epistemic and procedural legitimation work of COI units, this thesis discusses not only how the legitimacy of knowledge and procedures are constructed around notions of fairness and objectivity, but also how this process has a depoliticising effect on the politics of asylum by rendering refugee status and its determination technical. COI is then an important device in the bureaucratisation of asylum procedures and the depoliticisation of asylum.