The ruling on one who performs Hajj with forbidden money?

Question:
In another question, he says: When a person pays the cost of Hajj for one of his parents, and perhaps there is a doubt in this money regarding its being forbidden, and they know nothing about it, is their Hajj valid or not?

Answer:
If they did not know that this money is forbidden or that there is a doubt in it, then their Hajj is valid because of their lack of knowledge. If they knew that this money is forbidden, their Hajj is also valid, but with sin; they are sinful for using the forbidden money. However, if the rituals of Hajj are performed in the prescribed manner, the Hajj is valid despite the sin, and it is obligatory to repent to Allah the Exalted and Majestic from the forbidden money. If he gives in charity an amount equal to what he spent of the forbidden money, that is better for his conscience. Yes.
If this forbidden money is known to its owner, and it was taken from him without right and without his willing consent, then it is obligatory to return the money to him. If he does not know about it, then he gives it in charity to a needy person. Yes.