"Kommissar X" is a private detective named Joe Louis Walker who was a counterpart of the German crime fiction FBI Special Agent Jerry Cotton.
In addition to the vast collection of books, between 1965 and 1971 seven Kommissar X films were made with Tony Kendall as the laid back swinging New York City private eye Joe Walker balanced against the serious muscular New York City Police Captain Tom Rowland played by Brad Harris.
The Kommissar X series of crime novels were written by Bert F. Island whose real name was Paul Alfred Mueller (18 October 1901 – 1 January 1970).
[1] With the international success of the films of Ian Fleming's James Bond and the German Jerry Cotton (played by George Nader) series, seven Commissioner X films, mostly written and directed by Gianfranco Parolini and starring Tony Kendall as private detective Joe Walker and Brad Harris as New York City Police Lieutenant Tom Rowland, were made.
In 2012 a German comedy directed by Reginald Ginster titled Die X-Männer schlagen zurück featured Harris, Kendall and Parolini.