Lee Chan (Keye Luke) stated he was in Monte Carlo to show a painting. Luke was an accomplished artist in real life, specializing in murals.
This movie marks then end of an era and the beginning of a new one. Warner Oland would pass away seven months after the release of this film. It also marks the last time Keye Luke will play Charlie Chan's Number 1 son, Lee Chan in a Charlie Chan movie. He would reprise his roll as Lee Chan in Mr. Moto's Gamble (1938) a year later. Oland was just 58 years old at his passing. Sidney Toler picked up the Charlie Chan torch at the age of 64 with his first film Charlie Chan in Honolulu (1938). Charlie Chan's number 2 son, Jimmy Chan is played by Victor Sen Yung. Other Chan children make appearances throughout Toler's run of Charlie Chan series.
Harold Huber spoke French fluently, which he puts to good effect as the Chief of Police, Jules Joubert.