Summary of knowledge about the K source

At the end of 1941, Captain Edmond Combaux, Signals Officer, was assigned to the PTT (Postes, télégraphes et téléphones, the French administration of postal services and telecommunications) because of the downsizing of the Army required by the Armistice of June 22 1940. Combaux and Captain Léon Simoneau, an officer of the Army Intelligence Service had the idea to set up wiretaps to spy on German communications that had requisitioned most of the long-distance telephone lines in the Zone Occupée. This telephone network was maintained by the French PTT administration.

Combaux found complicity among the PTT staff including engineer Robert Keller and his team whose job was to intervene in the field, often at the request of the occupant to repair breakdowns or make new connections. A suburban house was rented along the Paris-Metz underground cable. in Noisy-le-Grand, in the name of Robert Jung who was the first operator trained by Simoneau. The operators were actually required to understand the German perfectly and to be skillfull in stenodactylo, but also to have a good knowledge of the operating structures of the German command. It was also necessary to develop a number of equipments, including high impedance amplifiers so that the Germans could not detect any anomaly on the cables.

On April 15, 1942, Robert Keller created an artificial defect on the Paris-Metz cable and received therefore a complaint from the Feldschalt-Abteilung, the German Direction of the long-distance lines. He was then given a proper mission order and began works at the vicinity of the cable route and opened several trenches, one of which was located by the Noisy-le-Grand rented house. On the night of April 18 to 19, Keller, Guillou and Matheron carried out the branching of 70 wires out of the 97 that were contained within the cable, benefiting from the complicity of both "verifiers" based in the repeater centers flanking Noisy-le-Grand: Lobreau at Paris-Saint-Amand center and Fugier in La Ferté-sous-Jouarre center. Both lobreau and Fugier were constantly surveyed by German technicians. The technical job was achieved quite successfully. At five o'clock in the morning, the branching was over, the cable was coated again in a sheath and the trench was closed. The 70 lines selected were those corresponding to the Kriegsmarine, Luftwaffe, Wehrmacht and Gestapo connections between Paris and Berlin.

Edouard Jung, who had an official front as an insurance agent, began his tapping work on April 20. He was then the single operator, but was quickly supported by Robert Rocard, brother of the physicist Yves Rocard and uncle of the future french prime minister Michel Rocard. In July 1942, a third operator joined the team, Prosper Riss. The work of the operators was very tiring, because not only did they spend a lot of time listening to the german communications, but then they had to retranscribe the records of the tapping with invisible ink.

Combaux used employees of the French railway compagny SNCF to send the tapping reports to Simoneau, in the Zone Libre. Simoneau and his chief, Colonel Rivet, sorted out this information, which then could be passed on to the chief of staff of admiral François Darlan, then commander-in-chief of the Vichy armed forces, or transmitted to the British through the various channels of communication between MI6 and the French intelligence agencies.

According to Edmond Combaux, the information provided was regarding the setting up and transformation of German large units of both the Wehrmacht and the Luftwaffe, submarine bases, assessments of the quality and behavior of leaders. Very top leaders were listened to: Hitler, Goering, Keitel, Von Rundstedt, Jödl, Stülpnagel ... The reports on the Dieppe operation in August 1942 revealed how all the German units reacted to this kind of events.

Tapping on the Paris-Metz line continued for five months, but the security of the house of Noisy-le-Grand became more and more threatened: the Germans had decided to establish a major unit east of Paris, in the area of Noisy-le-Grand, and for this purpose, they set up a vast operation to seek new cantonments and began to requisition housing. In the vicinity of the house rented by Jung, people were claiming to the town hall that before requisitioning the dwellings of the Noisy inhabitants, it would be better to take an interest in this house frequented by suspicious individuals. Combaux then decided to withdraw from this Noisy clandestine tapping station, and on the night of September 16 to 17, Keller and his team erased all traces of the branching.

This withdrawal of the Noisy station accelerated the execution of another similar operation on the Paris-Strasbourg cable. On the same model as in Noisy-le-Grand, a suburban house was rented by Prosper Riss, along the Paris-Strasbourg cable route. The Noisy amplifiers were installed in the new plant and the tapping was operational after Keller and his team achieved the branching on the night of December 16 to 17. Jung, Riss and Rocard could start their listening sessions, but between the cessation of Noisy's tapping and the commissioning of those of Livry-Gargan, the Zone Libre was invaded by German troops following the Anglo-American North Africa landing. French intelligence officers were pursued by the Germans. Combaux failed to trace his colleague Simoneau in Vichy. He left for Lyon on December 22nd, and when he came back on the 25th, he learnt that Keller had been arrested. On the morning of the 24th, when he had come to Livry-Gargan for service, Rocard was met by German soldiers but he managed a narrow escape.

Keller, Guillou, Matheron and Lobreau were deported and only Lobreau survived the deportation.

Edmond Combaux crossed the Spanish border in January 1943, then went on to London, joined the Free French Forces and was then assigned to the Free French BCRA (central bureau of Intelligence and Operations). In 1946, he reported that in May 1944 a senior officer of the British Admiralty told him that the information of "Source K" had proved of paramount importance. Leon Simoneau crossed the spanish border, like Combaux, in the course of January 1943, but joined his chief, Colonel Rivet, in Algiers. In April 1944, in a context of rivalry between the BCRA and the former intelligence services of the French Army, de Gaulle retired Rivet with the rank of general (actually, a dismissal) and promoted Simoneau at the head of SR Guerre (The intelligence agency of the french army) by transforming this body into SR "operationel" (SRO) of B army (future army of de Lattre who landed in Provence in august 1944), in formation. Simoneau died on April 7, 1993, and he had, in the words of Paul Paillole, kept his lucidity and exceptional confidence until his death… But he never left any testimony concerning the source K.

It remains to be seen how the Gestapo (it is indeed the Gestapo and not the Abwehr who intervened) was put on the trail of Robert Keller and the house of Livry-Gargan. Raymond Ruffin, the historian of the K source, who exploited essentially the 1946 report of Combaux, mentions an investigation after the Liberation which would have shown that the Gestapo was convinced a few days before the arrest of Keller, that there was a leak on the Paris-Strasbourg line.
On January 21, 1991, Le Point, a french weekly magazine published a compromising document regarding René Bousquet, The Secrétaire Général of the french Police under Laval government in 1942.This was a report from Himmler to Hitler dated 26 December 1942

This summary is drawn essentially from the book written by Raymond Ruffin, Résistance PTT, Presses de la Cité, 1983, which quotes as sources, concerning the Source K:

- Report of Henri Michel (Revue des P.T.T. de France No. 3)
- Report of Colonel Combaux (The Source K, 3-11-1946)
- Notes by Mr. Simon (Keller's Superior) (3-11-1946)
- Documents from the city of Noisy-le-Grand
And some notes from regional correspondents in the history of the PTT A documentary based on this book and broadcast in September 2018 on a French TV channel: “Hitler sur table d'écoutes”. In march 2019, this film can be downloaded on the internet.

Issues raised by Source K

There is no question of doubting the existence of Source K: A sufficient number of witnesses gave overlapping versions : The Paris-Metz and Paris-Strasbourg cables were hacked and German communications were listened to for 5 months on the Paris-Metz line.
We have never found any German archive reporting tapping of the Paris-Metz line. The Germans may never have known that they were being heard at Noisy-le-Grand. Maybe they discovered it, but they preferred not to pass this information back to Berlin.

Captain Simoneau on whom the tapping reports were converging left no testimony on this case, unlike his Intelligence colleagues ; Bertrand or Paillole or Navarre who wrote their memoirs.
It is even more embarrassing that the most important coup performed by the French intelligence services is not corroborated by any English work. To date, it seems that no English-speaking author has ever mentioned the K Source. Namely, Simon Kitson, who published his PhD work (The Hunt for Nazi Spies, University of Chicago Press ,2008 ) dealt a lot with the intelligence services of the Vichy army but did not mention the source K.

Many thanks to Arif Husein for his work in proofreading and correcting English

Remarques en Français

Ce texte en anglais est un résumé succinct de ce que l'on sait de la source K. Il a pour but de porter à la connaissance des historiens anglophones ce que l'on sait de la Source K dans le but de susciter des recherches dans les archives britanniques car il est vraiment génant de n'avoir aucune confirmation de l'apport de la source K aux Britanniques.