Who owns the increase (increase in value or growth) of the found property after the year has passed?
General Chapter
Al-Mughni
Book of Lost-and-Found Property
Primary text
If the found property experiences an attached increase after the year, the finder takes it along with the original property because the increase follows the original item in issues of defect correction and cancellation of sale. If a detached increase occurs after the year, it belongs to the finder because it is a distinct increase of his property that does not follow the original in cases of rescission, thus it belongs to him, like the increase of a sold item returned due to a defect.
Supporting text
There is an alternative view regarding the detached increase, based on the example of a bankrupt person whose property increases after it is repossessed, or a child's gift when the father reclaims what he gifted after it has increased. However, the correct view is that the increase belongs to the finder because he bears the liability for loss (Khiraj bi al-Daman), whereas in cases where he is not liable for loss, the increase might not belong to him.