§1. It is absolutely forbidden to sell sacred relics.
§2. Relics of great significance and other relics honored with great reverence by the people cannot be alienated validly in any manner or transferred permanently without the permission of the Apostolic See.
§3. The prescript of §2 is valid also for images which are honored in some church with great reverence by the people.
Source: Code of Canon Law (Vatican.va)