A study by an Iranian researcher, Javad Kazemitabar, at the University of California shows that around 12% of the Iranian cash flow is dirty money. Dr. Kazemitabar who gave a speech at the Center for Strategic Studies in Iran, has used datamining based to reach these results.
The topic became controversial at the national media, encouraging the necessity of joining the Financial Action Task Force (FATF) on money laundering. Currently Iran is not at the black list of FATF, however, not adopting the recommendations by the intergovernmental organization to fight money laundering may bring Iran back to its black list.
One of the reasons that FATF requirements in Iran has not yet been approved by the parliament is that some Iranian politicians believe that higher transparency at the financial systems will limit the ability of bypassing the US financial sanctions. Since now the return of the US sanctions seems very likely, Iran needs tricks to get access to its money abroad in the future.