Laundering money is taking money which you ought not to have e.g.money which is the proceeds of your crime or tax evasion and passing it through accounts, trading transactions (genuine or otherwise) or third parties so that it cannot be traced or identified as coming from your wrongdoing. The image is of making money clean, untainted by its illegal origins.The methods are various and may be complex. There's a whole lot of 'money laundering regulations' which banks, estate agents , solicitors and even antiques auctioneers, among others, have to comply with. We may guess that these businesses have proved innocent agents in such activity