Bleicher was recruited into the Abwehr during the Second World War because of his knowledge of French and Spanish, however, he never rose above the rank of Feldwebel. He was ruthless in his pursuit of anyone in France who opposed German domination. He disabled the Franco-Polish "Interallié" network, and captured both Polish Air Force Captain Roman Czerniawski and some of his headquarters staff, one of whom was Mathilde Carré, who had contacts with the Vichy2nd Bureau. She reportedly became Bleicher's lover, betrayed everyone she knew in the network, and agreed to act as an Abwehr agent. Subsequently, she changed sides again and betrayed her dealings with the Abwehr to MI5, who used her radio link for deception purposes for a period in conjunction with the Poles and the SIS and then imprisoned her when her usefulness had ceased, until the end of the war. In March 1943, Bleicher arrested André Marsac, a member of the resistance organisation known as Carte. Masquerading, on his own initiative, as a German intelligence colonel attempting to defect to the Allies, he deceived Marsac and his associate Roger Bardet, and persuaded Bardet to work for him as a double agent. Bardet betrayed SOE agents Peter Churchill and Odette Sansom who were arrested by Bleicher in April 1943. Sansom was subjected to brutal treatment and torture during interrogation before being transferred to a concentration camp, although none of this was carried out by Bleicher himself. Bardet betrayed the INVENTOR network, leading to the arrests in October/November 1943 of its organiser Sidney Jones, wireless operatorMarcel Clech, and courier Vera Leigh, all of whom were executed, and resulting in the collapse of the network. Bardet also betrayed Henri Frager, another former Carte member who had been commissioned by the SOE as leader of its Donkeyman circuit, whom Bleicher arrested in July 1944, and Frager was subsequently executed. He was also associated with SOE agent Henri Dericourt, who was also a double agent for the Sicherheitsdienst.
Postwar
Hugo Bleicher, together with two of his French Abwehr agents Jean Rocquefort and Francois Barbier, was arrested in Amsterdam on 15 May 1945 by the Dutch NBS, who interrogated him for two weeks on his activities in the Netherlands before handing him over to the First Canadian Army, who interrogated him for a further period, also on his operations in the Netherlands, before handing him over to the British authorities, who transferred him on 16 June 1945 to the UK for longer term interrogation at Camp 020. He was handed over to the French government on 12 October 1945, and they subsequently placed him on trial and imprisoned him, as they also did with Mathilde Carré. While imprisoned in Paris he met Bardet and told him he had planned to assassinate him on one occasion as Bardet knew too much against him. In 1954, he published his memoirs, Colonel Henri's story. Bleicher actively employed the aliases Jean Verbeck and Colonel Henri. He held, but never used, identity papers in the name of Jean Castel. He landed in the UK under the Canadian supplied alias of Charles Davidson, and has been misreported as using the names von Stahlen, Henri Bothereau or Gottschalk. He was decorated by the Abwehr with the WarMerit Cross 1st Class for his services.
