The Indian Evidence Act, 1872

Chapter 10 Of The Examination of Witnesses

Section 142: When they must not be asked

Leading questions must not, if objected to by the adverse party, be asked in an examination-in-chief, or in a re-examination, except with the permission of the Court.
The Court shall permit leading questions as to matters which are introductory or undisputed, or which have, in its opinion, been already sufficiently proved.

Less