Paul Temple

Paul Temple, a private detective slash crime novelist, began as a BBC radio serial in 1938 and made many returns right up through the 60's as well as several recent remakes. Four films were also made in the late 40's / early 50's and over a dozen novels have also appeared in the past 73 years. The character also had a large following in Germany with many German radio serials produced as well as an animated series. 
The TV program was co-produced by BBC and German broadcaster ZDF. 64 episodes were aired from 1969 to 1971 but only 11 episodes survive today.
http://en.wikipedia.org/wiki/Paul_Temple_%28TV_series%29