In 1977, France became the first nation to establish a permanent state agency dedicated to UAP investigation: GEPAN (later SEPRA, then GEIPAN), housed within the national space agency CNES. Over four decades GEIPAN analyzed roughly 3,000 cases from 8,000 testimonies, classifying approximately 7% as Category D, unexplained even after on-site investigation.

GEIPAN's methodology requires witnesses to complete structured questionnaires, and investigators coordinate directly with the French Gendarmerie and the Douanes for rapid sample collection. Cases classified D1 or D2 have persistent physical evidence or high witness consistency that survives cross-examination. In March 2007, GEIPAN published its full archive online, the first government UFO database made freely accessible to the public.