law: The Black Money (Undisclosed Foreign Income and Assets) and Imposition of Tax Act, 2015
  8. Powers regarding discovery and production of evidence.-
  (1) The prescribed tax authorities shall, for the purposes of this Act, have the same powers as are vested in a court under the Code of Civil Procedure, 1908 (5 of 1908), while trying a suit in respect of the following matters, namely:-
  (a) discovery and inspection;
  (b) enforcing the attendance of any person, including any officer of a banking company and examining him on oath;
  (c) compelling the production of books of account and other documents; and
  (d) issuing commissions.
  (2) For the purposes of making any inquiry or investigation, the prescribed tax authority shall be vested with the powers referred to in sub-section (1), whether or not any proceedings are pending before it.
  (3) Any tax authority prescribed for the purposes of sub-section (1) or sub-section (2) may, subject to the rules made in this behalf, impound any books of account or other documents produced before it and retain them in its custody for such period as it thinks fit.
  (4) Any tax authority below the rank of Commissioner shall not-
  (a) impound any books of account or other documents without recording his reasons for doing so; or
  (b) retain in his custody any such books or documents for a period exceeding thirty days without obtaining the approval of the Principal Chief Commissioner or the Chief Commissioner or the Principal Commissioner or the Commissioner.