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Triplex: More Secrets from the Cambridge Spies

TRIPLEX, or XXX, is the secret classification assigned to material illicitly copied from the diplomatic pouches of neutral embassies in wartime London.

TRIPLEX was acquired by a joint MI5 – SIS wartime operation to distract diplomatic couriers overnight with male and female prostitutes on their journeys home and copy the contents of the pouches. Invariably the couriers flew from Hull (to Stockholm) or from Bristol (to Lisbon) but their civil aircraft would be delayed by mechanical problems or adverse weather conditions, causing the pouches to be lodged overnight with the airport police, thus allowing the target to reacquaint himself with the attractive individual he first encountered hours earlier on the train. Once opened and photographed by technicians, the diplomatic seals would be replaced by a team of skilled craftsmen. The operation was conducted successfully throughout the war without incident and was never compromised. There is no reason to believe that any of the target diplomatic missions ever suspected their most confidential communications, usually letters, reports, documents and other items too valuable to entrust to the telegraph or wireless, had been accessed.

The operation was so secret that no mention of it has been made in any official history of wartime British intelligence. However, full details are to be disclosed in Moscow where the KGB archives have a collection of the TRPLEX product supplied by Anthony Blunt while he was the senior MI5 officer supervising the operation.

This book, which takes its title from the operation, includes a selection of authentic M5 and SIS documents never previously seen. This material amounts to the very first evidence of precisely what Kim Philby, Anthony Blunt and John Cairncross betrayed to their Soviet contacts.


“The first complete report on the Cambridge Five that gives the reader the opportunity to judge the extent of the damage done to the British... It will be greeted with enthusiasm by specialists in intelligence history.”

David Murphy, former CIA Chief of Soviet/Eastern Europe Operations

Nigel West Buy