1: If halal property gets mixed up in such a way that it is not possible to identify each from the other, and the owner of the haraam property and its quantity are not known, and if it is also not known whether the quantity of the haraam property is more or less than the due Khums , the person concerned should pay Khums, with the Niyyat of Qurbat on the entire property, to one entitled to receive Khums and such properties whose owners are unknown, and after the payment of Khums the balance will become halal for him.
This law is according to Aayatullah Sistani's Fatwa.