 Begun as a Charlie Chan film ("Charlie Chan at the Ringside"), but  upon difficulties between 20th Century FOX and Chan star Warner  Oland, the script was hastily rewritten to accommodate Foxs other  Asian sleuth, Mr. Moto. The presence of Chans son Lee is evidence  of the grafting of one movie onto another series. Though it has been  reported that Olands death was the cause for this change from Chan  to Moto, it is not the case. This film was released theatrically on  March 25th of 1938, while Oland did not die until August 6th of that  same year.