How can the one who collected illegal taxes repent when he is unable to return the rights to their owners due to their dispersal, the death of some, and the absence of others? Is it permissible for a relative to pay these rights from his own money to clear the tax collector's conscience, and to whom should these funds be paid and in what way?

Levying illegal taxes (Maks) is one of the major sins. If its perpetrator repents with sincere repentance, he will be forgiven, like those who commit other sins, in accordance with the Prophet's (peace be upon him) saying about the Ghamidiyyah woman: "Indeed, she has repented with such a repentance that if the levier of illegal taxes (sahib maks) had repented with it, he would have been forgiven." The conditions of repentance are: remorse, ceasing the sin, and resolving never to return to it, along with sincerity to Allah. If the sin involves the rights of another human being, then those rights must be returned or forgiveness sought from them. If unable to do so, one must increase good deeds.