(1) The Investigating Income Tax Authority may make such inquiries and investigations as it thinks fit in relation to any person or other person who is assessable to tax under this Act or within the scope of assessment of tax or may direct the said person or institution or any other person or institution concerned with such inquiry and investigation to supply or take measures to supply any documents related to the income or information under the control of the said person or institution at such time and place.

(2) The Board shall, for the purposes of this section, prepare a manual to be followed for the purposes of inquiry and investigation.