The Railways Act,1989
Section 7. Powers of Commissioner
Subject to the control of the Central Government, the Commissioner, whenever it is necessary so to do for any of the purposes of this Act, may-
(a) Enter upon and inspect any railway or any rolling stock used thereon;
(b) By order in writing addressed to a railway administration, require the attendance before him of any railway servant and to require answers or returns to such inquiries as he thinks fit to make from such railway servant or from the railway administration; and
(c) Require the production of any book, document or material object belonging to or in the possession or control of any railway administration, which appears to him to be necessary to inspect.