In the Shanghai bar scene, Lee Chan, Jr. (Richard Hatch) orders a "Captain Apollo on the rocks." Captain Apollo was Hatch's character on Battlestar Galactica (1978).
Because of Rachel Roberts' fragile psychological health, the producers had another actress on standby just in case Roberts became unwell to the point she could no longer work.
From 1926 to 1949, publicity for this movie stated that "Charlie Chan" appeared in one movie serial and forty-six movies, the most movies made about any fictional character. At the time of this movie, publicity also declared that the character had never been played by a Chinese actor.