Bring Back Lifeform, Priority One

I just rewatched, "The Thing from Another World" which was later remade into "The Thing." The thing is an alien that gets loose on a military base and starts killing people. The commanding officer radios for orders and is told that all measures must be taken to capture and protect the alien and to allow no harm to come to it. He then radios back that the alien can use quantities of human blood to both repair itself and to multiply, and that were it allowed to do so it could threaten the very existence of humanity. He receives a confirmation of the original order. I was wondering if this was the first instance in fiction where the heros are told by superiors that they must protect the evil creature that is currently doing it's best to kill them. The Thing from Another Planet was 1951. Are there any earlier fiction reference you can think of?