Dear Mr. Prohack (1949)

Arthur Prohack (Cecil Parker) is an official in the Treasury Department with a reputation for fiscal efficiency and running a tight ship. One day he finds out that a struggling businessman to whom he once loaned money used it to amass a fortune, and after his death he left much of it to Prohack. Despite his reputation for adeptly handling money at his job, he seems to be much less capable of handling his newfound riches.