Does ownership transfer when a usurper transforms usurped property into a different form?
General Chapter
Al-Mughni
Book of Usurpation
Primary text
The ownership of the original owner remains over the property even if the usurper (ghasib) transforms it, such as grinding usurped wheat, slaughtering and cooking a sheep, forging iron into tools, carving wood into a door, or cutting and sewing fabric. The original owner must take back the item and the usurper owes compensation for any depreciation in value. The usurper has no claim to any increase in value resulting from the transformation. This is the sound position in the madhhab and is the view of Al-Shafi'i. The proof is that the essence of the usurped item remains present, thus it must be returned, just as if the sheep was slaughtered but not cooked. Furthermore, if the usurper performed the act on his own property, ownership would not be removed from him, so performing it on another's property does not remove ownership from the original owner, similar to the case where one strikes gold nuggets into dirhams.
Supporting text
Abu Hanifa held that ownership transfers away from the original owner in all these cases. However, the usurper cannot dispose of the item unless he gives it away as charity, unless he pays the value, in which case he gains ownership and can dispose of it as he wishes. A narration from Ahmad suggests the usurper gains ownership by paying the value, but this is an old opinion he retracted.