Where, in the course of any proceedings under this Act, the Deputy Commissioner of Taxes, Additional Commissioner of Taxes (Appeals), Commissioner (Appeals) or Appellate Tribunal is satisfied beyond reasonable doubt that, with the return for any income year by the taxpayer or at any subsequent time the audit report submitted is not signed by the Chartered Accountant or is believed to be untrue, the said authority or, as the case may be, the Tribunal may impose a penalty of Tk. 1 (one) lakh on the said taxpayer for the said income year.