Operation Jungle was a program by the British Secret Intelligence Service (MI6) early in the Cold War (1948–1955) for the clandestine insertion of intelligence and resistance agents into Poland and the Baltic states. The agents were mostly Polish, Estonian, Latvian and Lithuanian exiles who had been trained in the UK and Sweden and were to link up with the anti-Soviet resistance in the occupied states (the Cursed soldiers, the Forest Brothers). However, the KGB penetrated the network and captured or turned most of the agents.
In the late 1940s SIS established a special center in Chelsea, London, to train agents to be sent to the Baltic states. The operation was codenamed "Jungle" and led by Henry Carr, director of the Northern European Department of MI6, Baltic section head Alexander McKibbin. The Estonian group was led by Alfons Rebane, who had also served as an Waffen-SS Standartenführer during Estonia's occupation by Nazi Germany, the Latvian group led by former Luftwaffe officer Rūdolfs Silarājs and the Lithuanian group led by history professor Stasys Žymantas.
The agents were transported under the cover of the "British Baltic Fishery Protection Service" (BBFPS), a cover organization launched from British-occupied Germany, using a converted former World War II E boat. Royal Navy Commander Anthony Courtney had earlier been struck by the potential capabilities of former E-boat hulls, and John Harvey-Jones of the Naval Intelligence Division was put in charge of the project and discovered that the Royal Navy still had two E-boats, P5230 and P5208. They were sent to Portsmouth where one of them was modified to reduce its weight and increase its power. To preserve deniability, a former German E-boat captain, Helmut Klose, and a German crew were recruited to man the E-boat.
Agents were inserted into Saaremaa, Estonia, Užava and Ventspils, Latvia, Palanga, Lithuania, and Ustka, Poland, all typically via Bornholm, Denmark where the final radio signal was given from London for the boats to enter the territorial waters claimed by the USSR. The boats proceeded to their final destinations, typically several miles offshore, under cover of darkness, and met with shore parties in dinghies. Returning British agents were received at some of these rendezvous.
The operation evolved into a number of phases. The first transport of agents occurred in May 1949, with six agents boarding the boat at Kiel. British officers, Lieutenant Commanders Harvey-Jones and Shaw sailed the boat to Simrishamn in Southern Sweden where Swedish officers replaced the British. The Swedes then proceeded via the cover of Öland Island, then east to Palanga, north of Klaipeda, arriving around 10:30pm. Within 300m of shore the six agents disembarked in a rubber dingy and made their way to shore. The boat returned to Gosport, picking up the British officers at Simrishamn and refueling at Borkum.
Following the success of the initial operation, MI6 followed up with several more improvised landings via rubber dingy. Two agents were landed at Ventspils on November 1, 1949; three agents landed south of Ventspils on April 12, 1950 and two agents in December at Polanda.
In late 1950, British Naval Intelligence and MI6 created a more permanent organisation with Klose hiring a crew of 14 sailors and basing the boat at Hamburg-Finkenwerder. The "British Baltic Fishery Protection Service" was thus invented as a credible cover story given the harassment of West German fishermen by the Soviets. The operation evolved with a secondary task of visual and electronic reconnaissance of the Baltic coast from Saaremaa in Estonia to Rügen in East Germany. For this purpose the boat was re-fitted with additional fuel tanks for extended range and an extensive antenna suite and American equipment for COMINT and ELINT. During this phase, four landings were performed between 1951 and 1952 with 16 agents inserted and five agents retrieved.
In August 1952, a second E-boat was put into service as a refuelling and supply vessel and consort for the SIGINT operations, under the command of Lieuntenant E. G. Müller, a former executive officer who served under Klose during World War II. Eight Polish agents were inserted during this period.
The operation was severely compromised by Soviet counter-intelligence, primarily through information provided by British double agents. In the extensive counter-operation "Lursen-S" (named for Lürssen, the manufacturer of the E-boats), the NKVD/KGB captured nearly every one of the 42 Baltic agents inserted into the field. Many of them were turned as double agents who infiltrated and significantly weakened the Baltic resistance.
One of the agents sent to Estonia and captured by the KGB, Mart Männik, wrote an autobiography "A Tangled Web. A British Spy in Estonia" which was published after his death and has been translated into English. The book gives an account of his experiences throughout and after the unsuccessful operation.
- Laar, Mart; Tiina Ets, Tonu Parming (1992). War in the Woods: Estonia's Struggle for Survival, 1944-1956. Howells House. p. 211. ISBN 0-929590-08-2.
- Peebles, Curtis (2005). Twilight Warriors. Naval Institute Press. pp. 38–39. ISBN 1-59114-660-7.
- Hess, Sigurd. "The Clandestine Operations of Hans Helmut Klose and the British Baltic Fishery Protection Service (BBFPS) 1945-1956". The Journal of Intelligence History (LIT Verlag Münster) 1 (2): 169–178.
- Männik, Mart (2008). A Tangled Web. A British Spy in Estonia. Tallinn: Grenader Publishing. ISBN 978-9949-448-18-0.
- Adams, Jefferson (2009). Historical Dictionary of German Intelligence. Scarecrow Press. p. 235. ISBN 9780810855434.