Provided that no deduction under this sub-section shall be allowed unless the assessee furnishes along with the return of income, evidence of payment of securities transaction tax in the prescribed form:

Provided further that the amount of deduction under this sub-section shall not exceed the amount of income-tax on such income computed in the manner provided in sub-section (2).

(2) For the purposes of sub-section (1), the amount of income-tax on the income arising from the taxable securities transactions, referred to in that sub-section, shall be equal to the amount calculated by applying the average rate of income-tax on such income.

(3) No deduction under this section shall be allowed in, or after, the assessment year beginning on the 1st day of April, 2009.

Explanation.—For the purposes of this section, the expressions, "taxable securities transaction" and "securities transaction tax" shall have the same meanings respectively assigned to them under Chapter VII of the Finance (No. 2) Act, 2004.