Section 105A(2) in The General Rules (Civil), 1957
(2)If a witness demands any sum in excess of what has been paid to him such sum shall be allowed if he satisfies the Court that he has actually and necessarily incurred the additional expense :Illustration. - A post office or railway employee summoned to give evidence is entitled to demand from the party, on whose behalf or at whose instance he is summoned, the travelling or other expenses allowed to witnesses of the class or rank to which he belongs, and in addition the sum for which he is liable as payment to substitute the officiating during his absence from duty. The sum so payable in respect of the substitute will be certified by the official superior of the witness on a slip, which the witness will present to the Court from which the summons issued.
