Reference: Fataawa wa Rasaa.il Shaykh ‘Abdur-Razzaaq ‘Afeefee – Page 474, Fatwa No.22
Question: The Shaykh was asked regarding a bedouin man who had stolen a camel, and when death approached him he instructed his son to return it [to it’s owner], however, his son does not know who the owner is?
Response: He should estimate the current price of the camel, i.e. on the day he intends to return [the camel] and not the day the camel was stolen, and then he should donate that amount to the poor and spend of it in good causes for the benefit of the Muslims.