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United Kingdom

Ministry of Defence (DEFE Series)

Defence Intelligence files on UFO sightings reported to the MOD, spanning 1948 to 2003. Two series from The National Archives at Kew: DEFE 24 (annual UFO report files and investigation records) and DEFE 31 (Defence Intelligence Staff assessments and policy documents).

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DEFE 24
Annual UFO Report Files
The MOD's year-by-year UFO investigation files. Each file covers sighting reports received during that period, investigation notes, witness correspondence, and internal assessments. Coverage runs from post-war 1948 through 2003.
75
Documents
1948 to 2003
Dates
Viewer Available
DEFE 31
Defence Intelligence Staff UFO Files
Structured sighting report forms (AF Form 413), police incident logs, DI55 assessments, and policy documents from the Defence Intelligence Staff. Includes Project Condign working papers and multi-witness triangle cases.
434
Pages
1996 to 1999
Dates

About This Collection

The UK Ministry of Defence maintained a UFO desk from the 1950s until 2009, when it officially closed its UFO reporting programme. Reports from the public and military were filed, assessed for defence significance, and retained in DEFE series files at The National Archives.

The DEFE 24 files are organised chronologically. Early files (1948 onwards) contain post-war sighting reports and assessment correspondence. Later files include the period covered by Nick Pope's tenure at the MOD UFO desk (1991 to 1994), during which the office received several hundred reports annually.

DEFE 31 contains the higher-level assessments, including working papers related to the Condign Report, a classified study completed in 2000 that examined UK UFO data and proposed explanations involving exotic atmospheric plasma phenomena.

Legend