Irregular investigation does not vitiate prosecution absent prejudice, where magistrate authorisation for police inquiry was obtained.

Section 17 of the Prevention of Corruption Act requires investigation by an officer of the prescribed rank unless competent Magistrate authorisation is obtained. Here, permission for the Sub-Inspector's investigation had been secured before the investigation proceeded, and the charge-sheet followed completion of that investigation. Any defect in authorisation was therefore, at most, an irregularity. An irregular or even illegal investigation does not by itself vitiate the prosecution or trial after cognizance and progression of proceedings, unless the accused shows prejudice or miscarriage of justice. In the absence of demonstrated prejudice, the challenge to the proceedings failed.

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Issues: Whether the order permitting a Sub-Inspector of Police to investigate the case under Section 17 of the Prevention of Corruption Act, 1988 was valid and whether any irregularity in investigation vitiated the proceedings in the absence of prejudice.

Analysis: Section 17 requires investigation by officers of the specified rank unless an order of the competent Magistrate is obtained. The order permitting the Sub-Inspector to investigate had in fact been obtained before the investigation proceeded, and the charge-sheet was filed after completion of investigation. The defect, if any, in the manner of authorisation was at the highest an irregularity in investigation. The settled position is that an irregular or even illegal investigation does not by itself invalidate the trial once cognizance has been taken and the proceedings have advanced to conclusion, unless the accused shows miscarriage of justice or prejudice caused by the defect.

Conclusion: The order permitting investigation by the Sub-Inspector was sustainable, and the challenge to the proceedings failed for want of demonstrated prejudice.

Ratio Decidendi: An irregularity in investigation does not vitiate the prosecution or trial unless it is shown to have caused prejudice or miscarriage of justice.

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