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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2DEFE Series

1948 to 2003Date Range

Viewer Available

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.

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.

Project Condign Report

The classified MOD study completed in 2000 examining UK UFO data. Three volumes plus executive summary: atmospheric plasma hypothesis, case analysis, and statistical review of reported phenomena.

Rendlesham Forest Files

The MOD's investigation files on the December 1980 Rendlesham Forest incident at RAF Woodbridge. Includes the Halt memo, witness statements, and internal MOD correspondence.

Statistical summaries published by the MOD UFO desk covering reported sightings across the UK, 1997 to 2006.

UK Yearly UFO Summaries

Annual sighting compilations listing every UFO report received by the MOD each year, with dates, locations, and brief descriptions. Coverage from 1997 through the programme's closure in 2009.

Defence Intelligence Staff records from DEFE 44 series, containing assessments and investigative files on unidentified aerial phenomena.

Pre-MOD Air Ministry records on UFO reports from the 1950s and 1960s. AIR 2 (correspondence) and AIR 20 (unregistered papers) series from The National Archives.

Individual sighting report forms filed with the British Ministry of Defence, 2002 to 2005. Standardised witness accounts with dates, locations, and object descriptions.

Declassified UFO Documents

MOD bulk declassification releases containing accumulated UFO investigation files, internal correspondence, and sighting assessments across multiple decades.

MOD internal reference material on UFO policy, research guidance documents, and background briefing papers for staff handling UFO reports.

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Guides

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.