Dear Rabbi Kornfeld,
Chullin 93B discusses when or if one can buy meat from an idolator. So far the discussion all centers on kashrut. Not discussed is the possiblity that the animal was used in idol worship. Why was idol worship not considered?
There is an argument in Avoda Zara (22b-23a) regarding whether animals of an idolator are considered as set aside for Avoda Zarah, with the main opinion being that they are not. However, I do not think that there is an opinion that any *meat* which is assumed kosher and is in the possession of a Nochri is assumed to be used in idol worship, as they probably did not normally offer already slaughtered meat as a sacrifice to their Avoda Zarah.
All the best,