Special Interrogation Group The Special Interrogation Group ( SIG ) ( some sources interpret this acronym as " Special Identification Group " or " Special Intelligence Group " ) was a unit of the British Army during World War II . It was organized from German - speaking Jewish volunteers from the British Mandate of Palestine . The SIG performed commando and sabotage operations against Axis forces during the Western Desert Campaign . Formation . The inspiration for the SIG belonged to Captain Herbert Cecil Buck , MC of the 3rd Bn . , 1st Punjab Regiment and later the Scots Guards , an Oxford scholar and German linguist . He had been captured in January 1942 , but had soon managed to break free and had then escaped back across Libya to Egypt , partly using German uniforms and vehicles . He was surprised by the ease of his deception and felt that , with greater planning and preparation , the concept could be used more offensively , to assist raiding parties attack key targets behind enemy lines . His plan was approved and , in March 1942 , he was appointed the commander of this new unit , the SIG . In March 1942 , Col . Terence Airey ( Military Intelligence Research at the War Office in London ) wrote that " a Special German Group as a sub - unit of M [ iddle ] E [ ast ] Commando . . . with the cover name ' Special Interrogation Group ' , to be used for infiltration behind the German lines in the Western Desert , under 8th Army . . . the strength of the Special Group would be approximately that of a platoon . . . The personnel are fluent German linguists . . . mainly Palestinian ( Jews ) of German origin . Many of them have had war experience with No . 51 Commando . . . " Some personnel was also recruited directly from the Palmach , Haganah and the Irgun . Other recruits came from the Free Czechoslovak Forces , the French Foreign Legion and German - speaking Jewish troops . The SIG was a part of D Squadron , First Special Service Regiment . Its strength varied between 20 and 38 , according to various sources . Training . According to ex - SIG member Maurice " Tiffen " Monju Tiefenbrunner , their first training base was located near Suez . The SIG were trained in desert navigation , unarmed combat , handling of German weapons and explosives . They were given fake German identities and were taught German marching songs and current German slang . For their missions , they were supplied with German pay books , cigarettes , chocolates , and even love letters from fictitious sweethearts in Germany . Walter Essner and Herbert Brueckner , two non - Jewish Germans , had been conscripted from a POW camp to train the SIG . Before the war , both had been members of the French Foreign Legion who had been captured in November 1941 serving in the 361st Regiment of the Afrika Korps and were subsequently recruited by the British Combined Services Detailed Interrogation Centre ( CSDIC ) as double agents . Operations and betrayal . The SIG drove captured German vehicles behind German lines near Bardia , set up roadblocks and carried out acts of sabotage . Dressed as German military police , they stopped and questioned German transports , gathering important military intelligence . On June 3 , 1942 , the SIG was assigned its first assault mission : They were to assist the Special Air Service , led by Lt . Col . David Stirling in destroying Luftwaffe airfields which were threatening the Malta Convoys . These airfields were located 100 miles west of Tobruk at Derna and Martuba in the Italian colony of Libya . During the raid , on the night of 13 – 14 June , Herbert Brueckner managed to run away , by faking an engine problem of the truck he was driving , and betrayed the Derna party , nearly all of whom were subsequently killed or captured . Essner , closely guarded by Tiefenbrunner throughout the raid , was handed over to the Military Police and later shot while trying to escape . Disbandment . On September 13 – 14 , 1942 , the SIG participated in Operation Agreement , the raid on Tobruk . Its objective was to destroy the Afrika Korps ' vital supply port . The SIG were to play the role of German guards transporting three truckloads of British POWs to a camp at Tobruk . The assault failed and the British forces lost three ships and several hundred soldiers and Marines . Surviving SIG members were transferred to the Pioneer Corps . Tiefenbrunner account of SIG . In January 1999 , Maurice ( Monju ) Tiefenbrunner , a surviving member of SIG , recorded his life story in an unpublished autobiography booklet called " A Long Journey Home " . On pages 37 – 41 , he provides information on SIG unit formation and operations . A sample scan of the first pages is shown to the right . After the SIG was disbanded , Tiefenbrunner was caught by the Italians , and sent to a POW camp in Italy . He was moved to a POW camp in Nazi German territory , where he met Vic Crockford . They were released in early 1945 . Film . The 1967 film " Tobruk " was about a raid of the SIG and the LRDG ( Long Range Desert Group ) on a German Afrika Korps fuel depot in Tobruk , starring Rock Hudson and George Peppard .