From 1934, a radio serial in 39 parts of 12 to 14 minutes each.
Tarzan and the Diamond of Asher was based on a three-page outline by Edgar Rice Burroughs. The actual writing and plotting was done by Robert W. Thompson. ERB's involvement beyond the outline was to read the finished scripts and make suggestions. In 1937, Burroughs used the plot for his novel Tarzan and the Forbidden City which was published in book form in 1938. Also in the same year, Burroughs adapted the radio show into a comic strip which was illustrated by Rex Mason and was published in 1938. (It was later adapted for a 1947 Dell comic book, adapted again for a comic strip in 1948-49, and finally adapted for a two-part Gold Key comic published in 1970.) Before book publication of the novel, Burroughs sent the manuscript to Argosy magazine where someone at the magazine considerably rewrote the work, which was published as "The Red Star of Tarzan." (Burroughs used his original manuscript for the novel publication.) Interestingly, when Tarzan and the Diamond of Asher was rebroadcast in 1940, Burroughs wrote a brief introduction to the series in which he claimed the radio serial was based on Tarzan and the Forbidden City, rather than the other way around.
The show began on May 14, 1934, airing Mondays, Wednesdays and Fridays through June 22. It was produced by American Radio Features, directed by Fred Shields, and narrated by John MacIntye.
Carson KaDell played Tarzan since Burroughs' son-in-law James Pierce refused of the role. (Joan Burroughs Pierce, his wife, was to play Jane but had bowed out because of a pregnancy; Pierce did not want to play Tarzan without his wife as Jane. The Jane character was then eliminated from the outline.)
The rest of the cast included Ralph Scott as D'Arnot, Karena Shields as Helen, George Turner as Gregory, Jeanette Nolan (who was John MacIntire's wife; they both would go on to prominent careers) as Magra, Cy Kendall as Atan Thome, Don Wilson (best known as Jack Benny's announcer) as Lal Taask, Victor Rodman as Wolf, Victor Potel as Larson, and Fred Harrington as Mitchell..