Well-Respected Man

1966. Recently married, Nick and Rosemary Storey overhear two foreign exchange traders boasting that they can get secret information from Civil Servants about a possible devaluation of the Pound. A squash club/wine bar in the City is supposedly where this information is passed on. But when the two men are found dead in the squash club, leaving a suicide note, Nick and Rosemary smell a rat, especially when it becomes clear that they entered the locked club and killed themselves without leaving any keys. Assuming that the deaths were linked to the men's boasting, they pursue various leads without getting very far until a chance conversation allows them to arrange for several suspects to be kept under surveillance. But unmasking them still involves Nick in skating on some very thin ice.
"A Well-Respected Man" is the latest in a series of books set mostly in Customs & Excise by Richard Hernaman Allen, a former Commissioner.