In some cases, illegal property may enter a person's assets. The owner of such assets must seek to remove the aforementioned property and return it to the true owner. However, the removal of illegal property is not easy in all cases and is sometimes even impossible because the entry of illegal property takes various forms. The results of this article, which is written in a descriptive-analytical manner, show that depending on the case, the determination of the ruling on illegal property will be different. It is possible that the amount of illegal property is certain but the owner is unknown and vice versa. In some cases, both the amount and the owner are unknown, but sometimes the amount and owner of illegal property are certain, in which case, in principle, returning the property to the owner does not face any obstacle. In many cases, the jurisprudence of the four Islamic schools of thought has prescribed expenses such as paying the property as khums or giving it as charity or handing it over to the treasury. In Imami jurisprudence, paying khums of property and making peace with the owner or giving charity is foreseen. The statutory law of Afghanistan lacks an explicit provision in such a case. Therefore, studying and analyzing the opinions of jurists of the five schools of thought can be useful and effective in reforming and updating the laws of Afghanistan.