Reference for Avodah Zarah 4:4
עֲבוֹדָה זָרָה שֶׁל נָכְרִי, אֲסוּרָה מִיָּד. וְשֶׁל יִשְׂרָאֵל, אֵין אֲסוּרָה עַד שֶׁתֵּעָבֵד. נָכְרִי מְבַטֵּל עֲבוֹדָה זָרָה שֶׁלּוֹ וְשֶׁל חֲבֵרוֹ, וְיִשְׂרָאֵל אֵינוֹ מְבַטֵּל עֲבוֹדָה זָרָה שֶׁל נָכְרִי. הַמְבַטֵּל עֲבוֹדָה זָרָה, בִּטֵּל מְשַׁמְּשֶׁיהָ. בִּטֵּל מְשַׁמְּשֶׁיהָ, מְשַׁמְּשֶׁיהָ מֻתָּרִין וְהִיא אֲסוּרָה:
The idolatry of a gentile is forbidden immediately, [it being written (Deuteronomy 7:25): "the carved images of their gods shall you burn with fire" — As soon as they are carved they are rendered "gods" for him. ] And that of a Jew is not forbidden until it is worshiped, [it being written in that respect (Ibid. 27:15): "Cursed be the man who shall make a carved or molten image … and do in secret" — [It is not forbidden] until he does "secret" things with it, i.e., until he worships it. For a Jew worships idolatry only in secret, fearing beth-din.] A gentile may nullify his own idolatry, [it being written (Ibid. 7:25): "The carved images of their gods shall you burn with fire" — when they relate to them as gods; but if he has nullified it, it is permitted] and (he may also nullify) that of a Jew, [when they are partners. (But this is not the halachah.) A gentile cannot nullify the idolatry of a Jew even if he has partnership in it.] And a Jew cannot nullify the idolatry of a gentile, [even if he permits him to do so]. If one nullifies an idol, he nullifies its appurtenances. (If he nullifies) its appurtenances, they are permitted and it itself is forbidden.