| Agency Name: | Second Investigation Department |
| Nativename: | Antrasis operatyvinių tarnybų departamentas |
| Seal: | Second Investigation Department (Insignia).png |
| Formed: | 27 October 1918 (restored 1 June 1990) |
| Jurisdiction: | Ministry of National Defence |
| Headquarters: | Jankiškių g. 50, LT-02300 Vilnius, Lithuania |
| Chief1 Name: | Brig. gen. Remigijus Baltrėnas |
The Second Investigation Department or AOTD (Lithuanian: Antrasis operatyvinių tarnybų departamentas) is a Lithuanian intelligence agency under the Ministry of National Defence. It conducts military intelligence as well as intelligence and counterintelligence in the areas of defense.[1]
The origins of the institution are in the Intelligence Unit established within the Lithuanian Armed Forces on 27 October 1918. In 1923, many intelligence activities were transferred to the Ministry of the Interior forming what later became the State Security Department of Lithuania. Military and defense related intelligence stayed within the General Staff and after 1929 the service was reorganized and named the Second Unit.[2]
After Lithuania regained independence in 1990, the department was reestablished as the Information Unit, later reorganized and renamed to the Second Investigation Department in 1997.[2] Its early task was to gather intelligence on Soviet military units operating in the region.[3] Since Lithuania became a member of NATO, AOTD has cooperated closely with the NATO intelligence community.[3]
| Name[4] [5] | From | To | Unit name | |
|---|---|---|---|---|
| 27 October 1918 | 12 May 1919 | News Unit, Intelligence | ||
| 12 May 1919 | 9 April 1923 | Intelligence Unit of the General Staff | ||
| Liudas Gira | 23 August 1919 | 9 November 1919 | Intelligence Unit of the General Staff | |
| 10 April 1923 | 24 January 1924 | Intelligence Unit of the General Staff, Third Unit of the General Staff | ||
| 24 January 1924 | 1 January 1926 | Information Unit of the General Staff | ||
| 1 January 1926 | 22 June 1926 | Information Unit of the General Staff | ||
| 22 June 1926 | 4 October 1926 | Information Unit of the General Staff | ||
| 4 October 1926 | 17 December 1926 | Information Unit of the General Staff | ||
| 17 December 1926 | 7 April 1930 | Information Unit of the General Staff | ||
| 7 April 1930 | 1 September 1930 | Second Unit of the General Staff | ||
| 1 September 1930 | 16 April 1934 | Second Unit of the General Staff | ||
| 16 April 1934 | 7 September 1934 | Second Unit of the General Staff | ||
| 7 September 1934 | 8 July 1940 | Second Unit of the Army Staff | ||
| Nazi and Soviet occupation (1940–1990) | ||||
| 1 June 1990 | March 1991 | Second Unit of the National Defense Department, Information–Intelligence Unit of the National Defense Department | ||
| April 1991 | May 1991 | Information–Intelligence Unit of the National Defense Department | ||
| 2 January 1992 | "A" Unit of Information Service | |||
| 7 May 1997 | Second Unit, Intelligence Department, Counterintelligence Department, Intelligence and Counterintelligence Department, Second Department of the Ministry of National Defense | |||
| 2 January 1992 | 21 April 1993 | Counterintelligence Department | ||
| 7 May 1997 | 4 January 2001 | Second Department of the Ministry of National Defense, Second Investigation Department | ||
| 4 January 2001 | 6 January 2007 | Second Investigation Department | ||
| 6 January 2007 | 1 August 2012 | Second Investigation Department | ||
| 1 August 2012 | 1 August 2016 | Second Investigation Department | ||
| 2 August 2016 | 13 August 2020 | Second Investigation Department | ||
| 13 August 2020[6] | Second Investigation Department | |||
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