law: 28. Powers of commissioners.-
  Subject to the control of the Central Government every commissioner shall have the power-
  (a) to enter upon and inspect any metro railway or any rolling stock used thereon;
  (b) to make any enquiry or to take any measurement as he thinks fit for the performance of his duties under this Act;
  (c) by an order in writing under his hand and official seal addressed to any metro railway administration, to require the attendance before him of any officer or other employee of the metro railway and to require answers or returns, to such enquiries as he thinks fit to make, from such officer or other employee or from the said administration;
  (d) to require the production of any book or other documents belonging to, or in the possession or control of, any metro railway administration which it appears to him to be necessary to inspect for the performance of his duties by or under this Act.