The National Forensic Science Laboratory (NFSL), Gandhinagar, has informed the Supreme Court that the audio recordings allegedly implicating former Manipur Chief Minister N. Biren Singh in the 2023 ethnic violence were found to be tampered with and unfit for forensic voice comparison.

The revelation came during the hearing of a plea seeking a court-monitored probe into the audio clips related to the violence that rocked Manipur last year. A Bench comprising Justice Sanjay Kumar and Justice Alok Aradhe examined the NFSL’s sealed report and directed that the final findings be shared with all parties, listing the matter for further hearing on December 8.

According to the NFSL report, “Four exhibits showed signs of modification and tampering. Therefore, they conclude that the clips are altered and do not constitute the original source recording and are not scientifically fit for forensic voice comparison.” Consequently, the laboratory said it could not offer any opinion on the similarity or dissimilarity between the questioned and control voice samples.

Appearing for the petitioner — the Kuki Organization for Human Rights Trust — Advocate Prashant Bhushan cited a separate forensic report by Truth Labs that had found a 50-minute clip (marked Y1) to be unedited and showing a 93% voice match probability with the control sample.

Justice Kumar assured Bhushan that the NFSL’s final report, dated October 10, 2025, would be provided to the petitioner for response. “We will give you the report so you can respond to it,” Justice Kumar said.

While Bhushan maintained that Truth Labs had a credible record, Justice Kumar observed that NFSL was considered the country’s premier forensic institution.

Solicitor General Tushar Mehta, appearing for the Union Government, emphasized that the NFSL report confirmed tampering and advised against further intervention, noting, “The situation in the state is now peaceful, so let’s not meddle with that.”

The case will next be heard on December 8.