Informant-Cum-Investigator Not a Per Se Ground for Acquittal; Current Law Applies to Pending Appeals — State of Punjab v. Gurnam @ Gama (2025 INSC 960)

Introduction

In State of Punjab v. Gurnam @ Gama etc. (2025 INSC 960), a two-judge Bench of the Supreme Court of India (Rajesh Bindal, J. and Augustine George Masih, J.) set aside a High Court acquittal that had rested exclusively on the rule in Mohan Lal v. State of Punjab (2018), namely, that an investigation is vitiated if the same officer is both the informant and the investigating officer. The case arises under the Narcotic Drugs and Psychotropic Substances Act, 1985 (NDPS Act).

The prosecution case alleged that on 20 September 2009, acting on secret information, the police intercepted a truck (Reg. No. PIX 0146) and recovered a very large quantity of poppy husk (about 750 kg) and two motorcycles. The two respondents were apprehended at the scene—Jaswinder Singh as the driver and Gurnam Singh @ Gama seated on the cargo. The trial court convicted both, imposing 12 years’ rigorous imprisonment and a fine of ₹1,00,000 each. On appeal, the High Court acquitted them solely on the basis of Mohan Lal (2018), without examining the evidence on merits.

The State appealed to the Supreme Court. The central issues before the Court were:

Whether the High Court could set aside the conviction solely because the same officer served as informant and investigator, without examining the facts and evidence.
How subsequent developments in law—Varinder Kumar v. State of H.P. (2019/2020) and Mukesh Singh v. State (Narcotic Branch Of Delhi) (2020, Constitution Bench)—affect pending appeals decided after Mohan Lal.
Whether the current legal position must be applied to appellate proceedings that are a continuation of the original prosecution.

Summary of the Judgment

The Supreme Court allowed the State’s appeals, set aside the High Court’s common judgment of acquittal, and remanded the matter to the High Court for a decision on merits. The Court held:

After Mohan Lal (2018), the three-judge Bench in Varinder Kumar clarified that pending prosecutions, trials, and appeals predating Mohan Lal should be decided on their own facts and Mohan Lal should not be a springboard for blanket acquittals.
The Constitution Bench in Mukesh Singh (2020) overruled Mohan Lal to the extent it mandated automatic vitiation of investigation where the informant and investigating officer are the same. The correct test is whether, on the facts, actual bias or prejudice is shown.
Since appeals are a continuation of the original proceedings, the law as it stands today applies; a mere technicality cannot determine the outcome without assessment of evidence.

Consequently, the Supreme Court directed the High Court to hear and determine the appeals expeditiously, given their vintage (trial in 2010, appeals filed in 2011).

Analysis

Precedents Cited and Their Influence

Mohan Lal v. State of Punjab (2018) 17 SCC 627: This decision held that fairness in investigation—integral to a fair trial—requires separation between the informant and the investigating officer. Several courts treated this as laying down a near-per se rule that an investigation is unfair if the same officer serves both roles, prompting a spate of acquittals.
Varinder Kumar v. State of H.P. (2020) 3 SCC 321 (2019 INSC 170): A three-judge Bench “clarified” Mohan Lal, warning that the criminal justice system cannot become “unidirectional” in favour of the accused by treating Mohan Lal as a vehicle for across-the-board acquittals. Importantly, it stated that all pending prosecutions, trials and appeals prior to Mohan Lal must be governed by their individual facts. This tempered the broad application of Mohan Lal in legacy cases.
Mukesh Singh v. State (Narcotic Branch Of Delhi) (2020) 10 SCC 120: A Constitution Bench conclusively held that merely because the informant also acted as the investigating officer, the investigation is not ipso facto vitiated. The question of bias or prejudice is fact-sensitive and must be assessed case by case. Mohan Lal, to the extent it mandated automatic acquittal, was specifically overruled.

The Supreme Court in the present case built its reasoning directly on Varinder Kumar and Mukesh Singh: because the respondents’ appeals were pending before Mohan Lal, the High Court should not have used Mohan Lal as a standalone basis for acquittal; and, in any event, Mukesh Singh now establishes that the informant-cum-investigator arrangement is not per se fatal.

Legal Reasoning

Appeals as a continuation of proceedings; current law governs: The Court emphasized that courts interpret, not enact, law. Appellate proceedings are a continuation of the original cause; therefore, the “law as available today” governs. Even if the High Court applied Mohan Lal when it was binding, the Supreme Court, reviewing the matter later, must apply the contemporary legal position clarified by Varinder Kumar and settled by Mukesh Singh.
No automatic acquittal on a technicality: The High Court’s error lay in allowing the appeal solely on the technical ground that the informant and investigator were the same, without evaluating the record. Varinder Kumar cautions against using Mohan Lal as a “springboard” for acquittal in pending/legacy matters, and Mukesh Singh rejects any per se invalidation. The Supreme Court, therefore, required a merits-based adjudication.
Balancing the rights of accused and prosecution: Quoting Varinder Kumar, the Court reiterated that the criminal justice system must balance the rights of the accused with society’s interest in effective prosecution. A categorical, automatic rule leading to acquittal without assessing actual prejudice would tilt the system “exclusively to the benefit of the offender,” which is impermissible.
Scope of materials beyond the trial record (antecedents): Although the State placed before the Court a list of criminal antecedents of one respondent (Gurnam @ Gama), and the defence objected to their placement without affidavit, the Supreme Court did not found its decision on such antecedents. Instead, it remitted the matter for a merits-based evaluation on the trial record by the High Court. In doing so, the Court implicitly reaffirmed that convictions or acquittals must primarily turn on legally admissible evidence concerning the offence charged, not on character or propensity.

Impact and Prospective Significance

End of automatic vitiation under the “informant-cum-investigator” objection: This decision reaffirms the Constitution Bench in Mukesh Singh and the clarificatory approach in Varinder Kumar, ensuring that accused persons cannot secure acquittal merely by demonstrating that the informant also investigated the case. Courts must inquire whether actual bias, prejudice, or unfairness is proved on the facts.
Guidance for High Courts in NDPS appeals: High Courts cannot dispose of NDPS appeals on a single technical ground without appraising the evidence. They must articulate reasons on the merits—compliance with statutory safeguards (search, seizure, sampling, chain of custody), credibility of witnesses, and overall probative value—while considering any alleged procedural lapses as part of a holistic prejudice analysis.
Stability in pending legacy cases: For prosecutions and appeals that predate Mohan Lal but remained pending when Mohan Lal was decided, courts should not treat Mohan Lal as determinative. Rather, they should apply today’s controlling law (Mukesh Singh) and decide whether the defence can demonstrate actual unfairness in the investigation.
Operational practice for police and prosecution: While the law does not require categorical separation of the informant and investigator, investigative agencies would still be well advised to separate functions where feasible, or to ensure rigorous documentation, supervision, and corroboration to minimize any allegation of bias. The prosecution should be prepared to demonstrate fairness and reliability irrespective of the officer’s dual role.
Substantive justice over technicalities: The decision signals the Court’s preference for substantive adjudication over procedural shortcuts, especially in serious offences like NDPS cases involving large commercial quantities. This may reduce technical acquittals and lead to a higher incidence of reasoned merits-based judgments.

Complex Concepts Simplified

Informant vs. Investigating Officer: The “informant” is the officer who receives or records the initial information (often leading to an FIR). The “investigating officer” collects evidence, interrogates witnesses, and builds the case. Mohan Lal had suggested these roles must be separate to ensure fairness. Mukesh Singh clarifies that combining these roles is not automatically unfair; the accused must show actual bias or prejudice.
Fair Investigation and Fair Trial: Indian constitutional law treats a fair investigation as an integral part of a fair trial. However, fairness is evaluated on the totality of circumstances, not by rigid formulas. An unfair practice must be shown to have caused real prejudice affecting the reliability of the prosecution case.
Prospective vs. Retrospective Application of Judgments: Courts normally interpret existing law and apply the interpretation to pending cases. “Prospective overruling” (applying a new rule only to future cases) is used sparingly and was not invoked here. Thus, appellate courts apply the law as settled at the time of their decision, even if it changed after the High Court ruling.
Appeals as Continuation of Proceedings: An appeal is not a fresh case; it continues the original prosecution. Therefore, legal developments between the trial and the appeal can and should be applied by the appellate court.
Technical vs. Substantive Acquittal: A “technical” acquittal rests on a procedural irregularity treated as automatically fatal. A “substantive” acquittal occurs when the evidence, on merits, does not establish guilt beyond reasonable doubt. This decision prefers substantive adjudication to ensure justice is not derailed by non-prejudicial technicalities.
NDPS Act Context: Offences involving poppy husk (poppy straw) under Section 15 are serious; large (commercial) quantities attract stringent minimum sentences. Courts scrutinize search, seizure, sampling, and chain-of-custody procedures closely—but must assess whether any lapse actually undermines reliability.

Practical Guidance Post-Decision

For Trial and Appellate Courts: When confronted with an informant-cum-investigator objection:
- Do not treat it as dispositive.
- Evaluate whether the defence has shown concrete bias or prejudice affecting the integrity of the investigation.
- Decide the case on the full evidentiary record, including compliance with statutory safeguards, corroboration, and credibility.
For the Defence: Focus on demonstrating specific prejudice—e.g., suppression of exculpatory material, selective recording, improper sampling or chain of custody, or contradictions—rather than relying solely on the dual-role objection.
For the Prosecution/Investigators: Even though not mandatory, separating the roles of informant and investigator can mitigate challenges. Where separation is not feasible, ensure meticulous documentation, independent witnesses where possible, robust chain-of-custody, and supervisory oversight to rebut allegations of bias.

What the Supreme Court Did Not Decide

The Supreme Court did not decide the respondents’ guilt or innocence.
It did not rely on the respondents’ alleged criminal antecedents to determine the outcome.
It did not lay down that Mohan Lal governs no case; rather, it reaffirmed that after Mukesh Singh, the correct test is case-specific assessment of prejudice, and that pending legacy cases cannot use Mohan Lal as an automatic ground for acquittal.

Case Trajectory and Key Dates

20 September 2009: Interception of truck and recovery of poppy husk; FIR registered.
11 December 2010: Trial Court convicts both respondents; 12 years RI and fine imposed.
16 August 2018: Mohan Lal decided by Supreme Court.
11 December 2018: High Court allows appeals solely relying on Mohan Lal; acquittal granted without merits analysis.
2019/2020: Varinder Kumar clarifies application of Mohan Lal to pending cases.
31 August 2020: Constitution Bench in Mukesh Singh overrules the automatic vitiation rule in Mohan Lal.
30 July 2025: Supreme Court sets aside High Court acquittal and remits for merits; directs expedited hearing.

Conclusion

State of Punjab v. Gurnam @ Gama reaffirms two critical propositions now controlling in criminal adjudication, especially NDPS matters:

There is no per se rule that an investigation is vitiated merely because the informant is also the investigating officer. Bias or prejudice must be demonstrated on the facts (Mukesh Singh).
Pending appeals are governed by the current state of the law. Mohan Lal cannot serve as a springboard for mechanical acquittals in legacy matters; courts must undertake a merits-based assessment (Varinder Kumar).

By setting aside an acquittal granted solely on a technical ground and remitting the matter for a reasoned merits determination, the Supreme Court steers the criminal process back to a balanced path—protecting the accused’s right to fair investigation and trial while safeguarding the community’s interest in effective prosecution of serious offences. The judgment is a clear directive to appellate courts: decide NDPS appeals on evidence and prejudice, not on formalistic shortcuts. It thus fortifies the jurisprudential shift from categorical rules to contextual fairness in criminal procedure.