By May 1942, the SIG was operational. Later, two
Luftwaffe pilots taken prisoner at the
First Battle of El Alamein provided additional details of the incident under interrogation. They claimed that the Germans knew that commandos dressed in German uniforms would attempt raids on German airbases in Libya and confirmed that Brueckner had betrayed the group. They also mentioned the capture of one of the SIG men. According to their testimony, the day after the raid a wounded man showed up at a German military hospital claiming to be a German soldier in need of treatment. The doctor became suspicious of him and on examination he was found to be Jew from Palestine. Essner, who had taken part in the Martuba raid and behaved well, was closely guarded by Tiefenbrunner on the way back to base and subsequently handed over to the military police. He was later shot while trying to escape. Simultaneous to the raid, another SIG operative, Karl Kahane, took part in a separate sabotage mission aimed at
Benghazi together with Stirling,
Paddy Mayne, and four other SAS commandos. Kahane talked them through the first German roadblock they encountered. They also passed an Italian roadblock but at a subsequent German checkpoint the Sergeant Major asked them the password. Kahane attempted to bluff his way through but the German was not satisfied and walked up to the truck. Mayne then cocked his revolver and the German ordered them to be let through, apparently having realized that they were British soldiers but that he would be shot in the event of a confrontation. With their cover blown, the team abandoned its original goal of Benghazi and struck nearby targets of opportunity, blowing up a roadblock, fuel tanks, pumps, trucks, and half-tracks before making a narrow escape while being chased by armored cars, exchanging fire with their pursuers before managing to get away. The news that soldiers of German origin were fighting with the Allies in North Africa made its way to
Adolf Hitler, who ordered that they be executed upon capture. On 13 June 1942, the
Oberkommando der Wehrmacht sent a secret message to
Panzer Army Africa which was intercepted by British intelligence and forwarded to Prime Minister
Winston Churchill stating: "Are said to be numerous German political refugees with Free French Forces in Africa. The Führer has ordered that the severest measures are to be taken against those concerned. They are therefore to be immediately wiped out in battle and in cases where they escape being killed in battle, a military sentence is to be pronounced immediately by the nearest German officer and they are to be shot out of hand, unless they have to be temporarily retained for intelligence purposes." On the night of 13/14 September 1942, the SIG participated in
Operation Agreement, the raid on the German and Italian stronghold of
Tobruk. Its objective was to destroy supplies in the port. A SIG team was to infiltrate the port as part of a large group of commandos in three trucks, with the SIG operatives playing the role of German guards transporting British POWs to a camp at Tobruk. The commandos were to assault the coastal guns east of the harbor. Buck would take part alongside Lieutenant David Russell, a
Scots Guards officer fluent in German. The group was led by Lieutenant Colonel John Haselden. As Buck correctly suspected that the Germans were by now aware of the SIG's existence, he assigned only a few SIG operatives to the mission rather than around a dozen as would have been preferable. The group successfully infiltrated the port and carried out the planned attacks after the aerial attacks began, capturing a villa to be used as the headquarters after overcoming the Italian platoon holding it. They cleared several more positions. The commandos then moved slightly inland, captured four anti-aircraft guns, and held their positions against Italian counterattacks intent on recapturing the guns. They eventually destroyed the guns by rolling grenades into the barrels. However, the naval and amphibious attack failed, with the British and other Allied forces losing three ships and several hundred soldiers and Marines. With no reinforcements coming and the enemy now regrouping, the raiders had to retreat, with Buck ordering the SIG men to destroy their German uniforms and documents. Haselden was killed while covering their escape. Some of the raiders were captured while those who escaped had to walk across the desert to rejoin Allied lines. One wounded SIG member was unable to go on after 17 days and agreed to be left behind. He was found by local Arabs and handed over to the Italians, who then turned him over to the Germans. He was tortured for five days and subjected to a mock execution, refusing to divulge any information. On the intervention of a German officer he was transferred to a POW camp. The raiders who escaped reached Allied lines after marching through the desert for more than a month. With the failure of the Tobruk raid, the SIG was disbanded. The remaining members were subsequently transferred to the
Royal Pioneer Corps. From there, several joined
No. 2 Commando and fought with the unit for the rest of the war. ==Tiefenbrunner account of SIG==