Port of New York is a 1949 film shot in semidocumentary style. The film is notable for being Yul Brynner's first movie. The film tells the story of a customs and treasury agent out to stop the distribution of opium, that came in on a ship in the Port of New York but was smuggled off by drug dealers. The leader of the drug dealers is the suave Vicola (Brynner).
You can stream Port of New York (1949) free and legally on OldReel, via the Internet Archive.
Yes — it is in the public domain and can be watched and shared freely.