Gideon Fell To Wake the Dead by John Dickson Carr 

1937 on the eve of King George VI's coronation, a woman is murdered in a grand London hotel. But this death is not the first of its kind...
Dr Gideon Fell:…………Donald Sinden
Superintendent Hadley:…………John Hartley
Sir Giles Gray:…………Richard Johnson
Melita Reaper:……….Wendy Craig
Chris Kent:…………David Brooks
Dramatized by Peter Ling
Produced and directed by Enyd Williams