Further info from TNA about SOE in Holland and in particular that the sorry events of "The Englandspiel" have been fully described in M R D Foote's official history of SOE in the Low Countries.
Holland
(KV 6/33-35)
SOE's work in Holland was the most seriously compromised of all their operations, with circuits thoroughly penetrated by the Germans, captured radio sets played back successfully and skilfully to SOE in London with false information, and scores of SOE agents parachuted directly into German hands. The sorry tale is fully described in M R D Foot's official history SOE in the Low Countries, and the story of SOE's slow realisation that its Dutch operations were hopelessly penetrated in Leo Marks' Between Silk and Cyanide.
KV 6/34 relates to Security Service interrogations of two agents, code-named SPROUT and CHIVE, who had managed to escape from Holland and were interrogated on their return to the UK, and to general SOE security in Holland. SPROUT was Pieter Dourlein, a secret army agent dropped into Holland in March 1943 and arrested on landing. Dourlein escaped in August 1943 and returned to Britain. He subsequently wrote about his experiences in the book Inside North Pole. CHIVE was Johan Ubbink, a radio operator parachuted in to Holland in November 1942, who escaped and returned with Dourlein. There is a summary of their case at folio 77a.
KV 6/35 continues the story, and includes a letter of protest from Ubbink at his arrest in May 1944 (which was done to protect Operation OVERLORD) and correspondence relating to the agents' appeals for assistance to the Dutch government in exile. The file includes suspicions voiced by Major Wethered that CHIVE may have been a double agent, and copies of reports of the two agents' interrogations. Both KV 6/34 and KV 6/35 are indexed.