"The benevolent and heroic Chan was conceived as an alternative to Yellow Peril stereotypes and villains like Fu Manchu." - American Western.
"famous British actor William Pratt (Boris Karloff)" played both Fu Manchu and Mr. Wong.
Karloff's father was the son of an Asian mother, and Karloff's mother was also part Asian.
When he came to play the character of Mr. Wong, detective, he broke ground by not resorting to the pidgin dialect and pseudo Confucian quips that marred the Charlie Chan films.
Link to the book:
Popular Comics 040