Industrial Disputes (Central) Rules, 1957
Any Commissioner appointed under these rules may unless otherwise directed by the order of appointment-
(a) examine the parties themselves and any witnesses whom they or any of them may produce, and any other person whom the Commissioner thinks proper to call upon to give evidence in the matter referred to him;
(b) call for and examine documents and other things relevant to the subject of enquiry;
(c) at any reasonable time enter upon or into any premises mentioned in the order.