rip off

First, thanks for this link. I haven't seen all of these movies (both originals and "rip-offs"), but the list certainly covered some parallels that I had noticed myself.

Actually, I just watched the "Comprehensive" version, and was describing it to my wife in terms of The Mask of Dimitrios (1944), before I hit IMDB and this post. Although I thought that Akim Tamiroff was a lot of fun, I have to say that I didn't think that the movie showed anywhere like the chemistry that Sydney Greenstreet and Peter Lorre had together.

But I think that we have to realize that there are a limited number of basic plots, and the artistry lies in what writers, directors, and actors can do with them. For instance, as another poster has noted, in addition to The Mask of Dimitrios (1944), this film also has some stuff in common with Citizen Kane (1941).

In fact, the whole "probing the personal history" plot probably started with King Oedipus's mission to unearth the cause of the plague in Thebes (https://en.wikipedia.org/wiki/Oedipus_the_King).