In holding inquiries under this Act, the officer holding the same shall have the same powers as are vested in courts in respect of the following matters under the Code of Civil Procedure, 1908 in trying a suit—

(a) proof of facts by affidavits,

(b) summoning and enforcing the attendance of any person and examining him on oath,

(c) ordering discovery and inspection, and compelling the production of documents,

(d) issuing of commissions.