Mandatory rank requirement for corruption investigations does not automatically void trial absent failure of justice.

Section 5(4) of the Prevention of Corruption Act, 1947 was treated as a mandatory safeguard requiring investigation by a police officer of the prescribed rank unless a Magistrate authorised otherwise. The requirement was understood to govern the investigation as a whole and to protect public servants from improper harassment. A breach of that restriction did not automatically invalidate cognizance or trial; the proceedings would be affected only if the illegality caused prejudice or a failure of justice. Where the objection was raised early, the court could take corrective steps, including reinvestigation, to preserve the statutory safeguard.

---

---

Issues: (i) Whether the restriction under section 5(4) of the Prevention of Corruption Act, 1947, requiring investigation by a police officer not below the rank of Deputy Superintendent of Police unless authorised by a Magistrate, was mandatory or merely directory. (ii) Whether a trial founded on an investigation conducted in breach of that restriction was vitiated, and what relief should follow where the breach was raised at an early stage.

Issue (i): Whether the restriction under section 5(4) of the Prevention of Corruption Act, 1947, requiring investigation by a police officer not below the rank of Deputy Superintendent of Police unless authorised by a Magistrate, was mandatory or merely directory.

Analysis: The statutory language was peremptory and was read with the scheme and policy of criminal investigation under the Code of Criminal Procedure. The provision was treated as a safeguard against harassment of public servants, substituting a higher-ranking investigating officer for the ordinary rule of cognizable investigation. The Court held that the requirement was not confined to any single step of investigation but governed the investigation as a whole, subject to the limited assistance permitted by the Code.

Conclusion: The restriction in section 5(4) of the Prevention of Corruption Act, 1947 was mandatory, not directory.

Issue (ii): Whether a trial founded on an investigation conducted in breach of that restriction was vitiated, and what relief should follow where the breach was raised at an early stage.

Analysis: A defect in investigation was held not to destroy the competence of the court or the validity of cognizance and trial in every case. The breach did not automatically nullify the proceedings unless it caused failure of justice. At the same time, if the illegality was brought to the court's notice early, appropriate corrective steps could be taken, including reinvestigation, so that the statutory safeguard would not be reduced to a dead letter.

Conclusion: An illegal investigation did not by itself vitiate the trial; interference depended on prejudice or failure of justice, and early correction by the trial court was permissible.

Final Conclusion: The common legal questions were answered by holding the investigation restriction mandatory, but the effect of breach depended on the facts of each case. On that basis, one appeal was rejected, two appeals were sent back for reconsideration, and the remaining appeal was declined with liberty to raise the objection before the trial court.

Ratio Decidendi: A statutory restriction on the rank of the investigating officer may be mandatory, yet an illegality in investigation does not by itself invalidate cognizance or trial unless it has occasioned a failure of justice.

---