The Code of Criminal Procedure, 1973 (CrPc)
296. Evidence of formal character on affidavit.
(1) The evidence of any person whose evidence is of a formal character may be given by affidavit and may, subject to all just exceptions, be read in evidence in any inquiry, trial or other proceeding under this Code.
(2) The court may, if it thinks fit, and shall, on the application of the prosecution or the accused, summon and examine any such person as to the facts contained in his affidavit.