November 2, 1943 Allen Dulles gets inside information that WS “intends to try to get in touch with 110 [Allen Dulles] either directly or through indirect means. He often goes to Switzerland and believe he is in touch with 511 [Swiss Intelligence] chief which bothers us some.”
Petersen, Neal H. From Hitler’s Doorsteps The wartime intelligence Reports of Allen Dulles 1942-1945 © 1996 University Park, Pennsylvania – Pennsylvania State University Press, p 149 Telegram 965


May 15, 1944: futher to his concerns already expressed on his 2 November 1943, Allen Dulles warns Washington that “outside information, beyond the Wood material, point to a perilously close association between Masson, the head of Swiss G-2, and Schellenberg of the Gestapo and forces me to reach the conclusion that the Nazis are receiving information from certain officials in the Swiss intelligence Service… I’m disturbed at the convincing nature of this evidence… With the above in mind, I believe that we should earnestly contemplate presenting evidence (the Wood material included) in strictest secrecy to the highest Swiss Quarters to prove to them that material is handed over to the Nazis from here, which has been obtained in confidence from the Allies…” Allen Dulles thinks that he should advise General Guisan personally and on May 20 asks permission, but on May 25 is denied authorization as it could compromise Fritz Kolbe (codename “Wood”) From then on Dulles will no longer pass information to the Swiss and receive their information with analytical caution.
Petersen, Neal H. From Hitler’s Doorsteps The wartime intelligence Reports of Allen Dulles 1942-1945 © 1996 University Park, Pennsylvania – Pennsylvania State University Press, p 239 Telegram 2460-64

... et avant que vous vous aventuriez trop, il existe des messages postérieurs montrant que Le Général Guisan (que Dulles estime, alors qu'il considère Masson comme un ennemi) transmet des informations sur la composition de forces à la frontière de la Suisse comme étant composée de forces du front de l'Est au repos ou à l'entrainement mais dissimulant des forces aguerries et des forces aériennes... avec le message encore postérieur de Dulles rapportant que les informations de Guisan sont en fait de la désinformation et qu'il n'y a, vérification faite, aucune troupe aguérie ou aérienne à l'endroit indiqué.