Reference: http://www.alfawzan.af.org.sa/node/16292
Question: How do I rid myself of haraam wealth if it has become mixed-up with my halaal wealth which I have earnt in accordance with the Islaamic Sharee’ah?
Response: You are required to carefully estimate the [amount of] haraam [money] from your wealth, then give it away to the poor and needy. [And this is] not [to be done with the intention] as charity, rather, as an act of ridding yourself of haraam [wealth] to absolve yourself of the responsibility, as this [haraam] money is considered to be that which has no owner – in which case it is to be given to the poor and needy.