Jeff Regan, Investigator

Jeff Regan, Investigator is a radio detective drama that ran on CBS from July 10, 1948 to December 18, 1948, and again from October 5, 1949 to August 27, 1950. The series is notable for being one of the earliest nationwide programs to feature Jack Webb.
Production.
Webb, who had previously starred on the Mutual detective drama, "Johnny Madero, Pier 23", played the title character, a private investigator working for Anthony J. Lyon at the International Detective Bureau. In the first incarnation of the series, Lyon was played by Wilms Herbert, while Webb's future "Dragnet" co-star, Barton Yarborough, played his co-worker, Joe Canto. This format continued until the end of the year, when Webb left the program. According to writer William Froug, Webb was fired for asking for too much money.
The program remained on hiatus for almost a year before being brought back with voice actor Frank Graham portraying Regan. Graham, who was well known both as an announcer and for his versatility, had previously created and starred in his own detective series, "The Adventures of Cosmo Jones". Lyon was also recast, with "The Jack Benny Program" regular Frank Nelson taking over the part. This remained the definitive lineup for the rest of the show's run, although for unknown reasons Paul Dubov filled in for Graham for several weeks.
Cancellation.
The second version of "Regan" remained popular in the ratings and was expected to be renewed for another season. However, Graham committed suicide on September 2, 1950. At the time of his death, five more broadcasts were scheduled for "Regan", but they were never completed. Graham had completed an episode scheduled to air the night after he died, but newspaper accounts indicated that CBS chose not to broadcast it. The role of Regan was not recast, resulting in the series ending production permanently.