The Central Bureau of Investigation (CBI) has filed an affidavit in the Supreme Court detailing multiple ‘acts of omission’ by former Kolkata Police chief Rajeev Kumar during his stint as head of the special investigation team that probed a series of ponzi schemes, including the Saradha and Rose Valley chit funds, which duped investors of over Rs 20000 crore over a five year period between 2009 and 2014.