law: 4. Authority to try a petition.-
  (1) Every petition shall be tried by an Authority, constituted for the purpose by the Central Government by notification in the Official Gazette.
  (2) The Authority shall consist of a single member, who is a Judge of the Supreme Court, to be nominated in this behalf by the Chief Justice of India.
  (3) If for any reason a vacancy occurs in the office of member aforesaid, the Chief Justice shall, as soon as practicable, nominate a person to fill the vacancy, and thereupon the trial of the petition shall be continued as if that member had been the Authority from the commencement of the trial of such petition:
  Provided that the Authority may, if it thinks fit, recall and re-examine any of the witnesses already examined.