Suppose we have an accelerated rigid body that possesses angular momentum. Then the body will undergo Thomas precession, and if the angular momentum vector of the body is not aligned with the axis of the Thomas precession, the angular momentum vector of the body will precess when viewed in an inertial frame. The angular momntum thus changes in time in the absence of any externally-applied torque. This would seem to me to be in conflict with the principle of conservation of angular momentum. I did a limited literature search and found one paper related to this question, by Muller, "Thomas Precession: Where's the Torque?", Am. J. Phys. 60(4). Muller says that Thomas precession actually does cause a torque, and so angular momentum conservation is not violated. Seems to me though that since the Thomas "torque" is not externally applied, it does not remedy the situation. Am I missing something obvious here? Does anybody know of additional discussion of this in the literature?