"Boston Blackie's Chinese Venture" is the last in the Boston Blackie series, filmed in 1949. Thanks to Blackie, Chester Morris had to return to the theater, as he was quoted as saying, "After ... these films, a producer wouldn't put me in an 'A' movie even if I paid for the privilege."
Without the good-looking, amusing Morris as Blackie, the series would not have worked as well as it did. The stories were usually very formulaic, and you really had to love the Runt in order for him not to become annoying. (The Runt here is Sid Tomack and not George E. Stone.)
This story is actually kind of interesting - Blackie gets involved with a diamond smuggling ring in Chinatown after the owner of a laundry is found dead right after Blackie dropped off his laundry! Of course, as usual, he has to clear his name or be arrested by Inspector Farraday.
The fun part about this film is the underground Chinese tours for tourists showing gambling, dancing slave girls, etc. - all fake, with the performers dropping their acts as soon as the tour guide moves on.
Sorry to see Blackie go, but it became a TV show in the '50s starring Kent Taylor, a very different type from the amiable Morris.