Are you sure it is a solid piece of wood? During WW2, when all metals were rationed, several American toy companies made figures from a plaster (wood flour, starch, whiting, and water,) that was kneaded into a dough mixture , then hydraulically forced into molds. With the "seam", is it possible this is one of them? Sub
Maybe just a split on the grain? Sometimes when I cut wood I end up with one of those little lines/bumps in the middle - from cutting from both sides with smallish saw. Looks like on of those Italian Anri carvings to me.
It bears a strong resemblance to some of the old Italian ANRI carvings but without any kind of markings to help identify its maker you may never know for sure.