Chinese detective movies aren't remembered as the most culturally sensitive things, which makes this little confrontation in "Phantom of ChinaTown" (1940) all the more interesting.
In this scene detective James Lee Wong is visiting the home of a famous archaeologist to investigate a murder:
Boris Karloff also played Detective Wong in several movies and was criticized for not using a chinese accent. But here we have Keye Luke and he doesn't use a chinese accent either. Perhaps Warner Oland had the exclusive rights to silly chinese accents.
"Phantom of ChinaTown" is a rather modest movie, but interesting for the diplomatic manner in which Luke plays the lead role. It is in the public domain and you can download it at www.archive.org.
Footnote: I tried dictating this post with voice recognition software. "The Phantom of ChinaTown " was transcribed as "the Clinton agenda talent". Maybe all those columnists we regard as right-wing nuts just need to go back to manual typing.