There's money laundering; have a front business and gradually mix in a bit of the illegal money and pretend it came from the business. That's how mobsters do it.
>>not2b+(OP)
That's right; your comment brings to mind this scene where the character Saul Goodman explains money laundering in Breaking Bad (this clip is supposedly shown as part of university lectures): https://www.youtube.com/watch?v=RhsUHDJ0BFM