Fair investigation under NDPS law requires separation of informant and investigator; bias can vitiate conviction and trial fairness.

In NDPS prosecutions, a fair and impartial investigation is essential before the reverse burden of proof can operate. The text states that where the informant also conducts the investigation, material seizure and custody witnesses are not examined, seized contraband is not promptly deposited in the malkhana, and sample dispatch is delayed without explanation, the investigation is seriously infirm and Article 21 fairness is undermined. The stated conclusion is that the informant and investigating officer must not be the same person, and the conviction was unsustainable because the investigation stood vitiated.

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Issues: Whether, in a prosecution under the Narcotic Drugs and Psychotropic Substances Act, 1985, the informant and the investigating officer can be the same person consistently with the right to a fair investigation and fair trial.

Analysis: The prosecution case was found to be seriously infirm because the informant himself conducted the investigation, material witnesses connected with seizure and custody were not examined, the seized contraband was not promptly deposited in the malkhana, and there was unexplained delay in sending the sample for chemical analysis. In a case governed by a reverse burden of proof, the prosecution must first establish the foundational facts through a fair and impartial investigation before the burden shifts to the accused. A fair trial under Article 21 is undermined where the investigation itself creates a real apprehension of bias or a predetermined result. The requirement of fairness is therefore not satisfied by merely alleging compliance with procedure or by relying on the statutory presumptions under the NDPS Act.

Conclusion: The informant and the investigating officer must not be the same person, and the conviction was unsustainable because the investigation stood vitiated.

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