Proceed with Caution is a 1937 detective novel by John Rhode, the pen name of the British writer Cecil Street.^[1][2] It is the twenty-seventh in his long-running series of novels featuring Lancelot Priestley, a Golden Age armchair detective. It was published in the United States the same year by Dodd Mead under the alternative title Body Unidentified.^[3]

Superintendent Hanslet and Inspector Waghorn of Scotland Yard respectively investigate a diamond robbery and a suspicious death. A consignment of valuable jewels have gone missing while being transported from Hatton Garden. Meanwhile a corpse is found in a tar burner in a Kent village, completely unrecognisable. It takes the genius of Dr. Priestley to demonstrate how these two events are linked.

E.R. Punshon writing in The Guardian felt " If only Mr. Rhode were a little more careful with his characterisation, if only his literary style were a little less pedestrian, he would take an even higher place than that his persistent—and consistent—ingenuity has won for him."^{[citation needed]}

• Evans, Curtis. Masters of the "Humdrum" Mystery: Cecil John Charles Street, Freeman Wills Crofts, Alfred Walter Stewart and the British Detective Novel, 1920-1961. McFarland, 2014.
• Magill, Frank Northen . Critical Survey of Mystery and Detective Fiction: Authors, Volume 3. Salem Press, 1988.
• Reilly, John M. Twentieth Century Crime & Mystery Writers. Springer, 2015.