Corridors Of Secrecy (AKA Chinese Whispers)

Nick Storey is asked to carry out a review of Cabinet Office security procedures, but learns from a contact in MI6 that the real purpose is to identify a mole leaking secrets to the Chinese.

Making slow progress because of the defensive attitudes by Cabinet Office staff, he is diverted by a botched Investigation Division operation in Liverpool against a Chinese smuggling gang.

Sorting that out gives him an idea how the microfilms with leaked secrets are sent to Hong Kong. A Chinese meal with the Cabinet Office "foo-yung club" in Soho, gives Rosemary the chance to spot how the microfilm is handed over. Discrepancies between what Cabinet Office staff and security guards say and the discovery of a secret door used by the "Cabinet Office ghost" narrows the field of suspects and a C&E operation nets the courier with the microfilm. What happens next makes a corkscrew look straight.
"The Corridors of Secrecy (aka Chinese Whispers" is the 17th book in a series of detective stories.