File Title 'C', Chief of the Secret Intelligence Service (SIS): Secrecy of CX (Intelligence) and Y (Signals Intelligence) Messages
Reference FO 1093/310
Date 11 January 1940 - 8 November 1940
Government Department Foreign Office
File Accession Date 23 May 2013


A file of correspondence and intercepted communications concerning breaches of security. The documents include several letters warning about cavalier treatment of confidential sources of information, posing a threat to their existence, and several more complaining about similar behaviour regarding classified documents. The file also contains a copy of an intercepted telegram sent to Tokyo in 1940 by the Japanese ambassador in Cairo, giving information about Anglo-French strategy in the Mediterranean gleaned from conversations with senior generals, along with British orders restricting conversations with Japanese diplomatic personnel.

Cookies Notification

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Find out more.