Warner Oland kept falling asleep during a race track scene, so director H. Bruce Humberstone included a lot of noisy extras in the shot to keep the actor awake.
The footage purporting to be the Melbourne Cup was not shot in Melbourne. The Flemington grandstand (1924), still standing, is different, as are the grounds, and horse races are conducted on grass in Australia, not on dirt.
In an advert for a preview showing, (New York Sun, 13 August 1936)
the film is billed as "AT THE RACE TRACK WITH CHARLIE CHAN".
While many here refer to the race track as "Santa Anita" the track in the film is called "Santa Juanita" which doesn't exist.
H. Bruce Humberstone: The director has a small uncredited role as the gambler who causes the Chans to be kidnapped.