Hazrat Zuhri (may Allah have mercy on him) says regarding the person who comes into possession of unlawful wealth: If he wishes to rid himself of that wealth, then he should dispose of it.

It is narrated from Hazrat Malik bin Dinar that a person asked Hazrat Ata bin Abi Rabah, "A person has acquired unlawful wealth, what should he do?" He replied, "He should return it to its owner, and if the owner is not known, then he should give it in charity. I do not know whether by doing so his sin will be absolved."

A person asked Hazrat Ata that I was a slave and I acquired some wealth through means that I do not like; now I want to repent! He replied: Return the wealth to its owner. I said: I do not know them. He said: Give it in charity; you will not get any reward, and I do not know whether its sin will be upon you or not. The narrator says that I asked Hazrat Mujahid about this matter; he also replied in the same way.

24660 - (He said) (1): (And I asked) (2) Mujahid, and he said: the same as that.

It is narrated from Hazrat Rabee’ that a person asked Hazrat Abu Ja’far (may Allah have mercy on him):“My friend acquired unlawful wealth, then he mixed all of it with his family and their wealth. Later, when he realized the evil and wrong in it, he spent all that wealth on Hajj and on the neighbors of the House of Allah. What is your opinion regarding this?”Hazrat Abu Ja’far replied:“He should fear Allah and not do such a thing again.”

It is narrated from Hasan that if a person has collected someone else's wealth or has stolen someone's wealth, and he wants to return it in such a way that the owner does not know (is not aware of it), so he delivers the goods to him, then there is no harm in it.