(1) In discharging their functions by or under this Act, the Tribunal and the Commissioner shall have all the powers of a Civil Court for the purpose of—
(a) proof of facts by affidavit;
(b) summoning and enforcing the attendance of any person, and examining him on oath or affirmation;
(c) compelling the production of documents; and
(d) issuing commissions for the examination of witnesses.
(2) Without prejudice to the provisions of any other law for the time being in force, where a person, to whom a summons is issued by the Tribunal or the Commissioner either to attend to give evidence or produce books of accounts, registers or other documents at a certain place and time, intentionally omits to attend or produce the documents at the place and time, the Tribunal or the Commissioner, as the case may be, may impose on him such fine not exceeding five thousand rupees as it or he thinks fit;
and the fine so levied may be recovered in the manner provided in this Act for recovery of arrears of tax:
Provided that, before imposing any such fine, the person concerned shall be given a reasonable opportunity of being heard.
(3) If, any documents are produced by a person or dealer on whom a summon was issued by the Commissioner, and the Commissioner is of the opinion that any dealer has evaded or is attempting to evade the payment of any tax due from him and the documents produced are necessary for establishing the case against such dealer, the Commissioner may, for reasons to be recorded in writing, impound the documents and shall grant a receipt for the same, and shall retain the same for so long as may be necessary in connection with the proceedings under this Act, or for a prosecution under any law.