If the ¹ [Assesing Officer] or the ² [Chief Commissioner or Commissioner] (Appeals) in the course of any proceedings under this Act is satisfied that any person has concealed particulars of chargeable expenditure or has furnished inaccurate particulars of such chargeable expenditure, he may direct that such person shall pay by way of penalty, in addition to any expenditure-tax payable by him, a sum which shall not be less than, but which shall not exceed twice, the amount of tax sought to be evaded by reason of concealment of particulars of chargeable expenditure or the furnishing of inaccurate particulars of such chargeable expenditure:
     Provided that if the amount of chargeable expenditure (as determined by the ¹ [Assessing Officer] on assessment) in respect of which particulars have been concealed or inaccurate particulars have been furnished exceeds a sum of twenty-five thousand rupees, the ¹ [Assessing Officer] shall not issue any direction for payment by way of penalty without the previous approval of the ³ [Additional Commissioner or, as the case may be, of the Deputy Commissioner].