Post Office Investigator is a 1949 black and white American crime film about the theft of postage stamps, directed by George Blair, and starring Audrey Long, Warren Douglas and Jeff Donnell.

[1] Allmovie called it a "diligent Republic programmer.

"[2] A young postman becomes involved in the theft of rare stamps featuring inverted images of the Statue of Liberty.

Along the way he encounters attractive criminal Clara Kelso, double-crossing gang members, and Post Office Inspectors, before finally capturing the crooks.