16. If the Excess Profits Tax Officer, the Appellate Assistant Commissioner or the Commissioner, in the course of any proceedings under this Act, is satisfied that any person has, without reasonable cause, failed to furnish the return required under sub section (1) of section 13, or to produce or cause to be produced the accounts or documents or other evidence required by the Excess Profits Tax Officer under sub section (2) of that section, or has, either in the said proceedings or in any earlier proceedings relating to an assessment in respect of the same chargeable accounting period, concealed particulars of the profits made by or capital employed in the business, or has deliberately furnished inaccurate particulars of such profits or capital, he may direct that such person shall pay by way of penalty, in addition to the amount of any excess profits tax payable, a sum not exceeding-(a) where the person has failed to furnish the return required under sub section (1) of section 13, the amount of the excess profits tax payable; and(b) in any other case, the amount of excess profits tax which would have been avoided if the return made had been accepted as correct: Provided that the Excess Profits Tax Officer shall not impose any penalty under this section without the previous approval of the Inspecting Assistant Commissioner.