NFSL to SC: Manipur audio tapes altered, cannot confirm N Biren Singh voice

Guwahati: The National Forensic Science Laboratory (NFSL), Gandhinagar, informed the Supreme Court that someone tampered with the audio recordings allegedly implicating former Manipur Chief Minister N. Biren Singh in the 2023 ethnic violence, making them scientifically unfit for voice comparison.

Consequently, the laboratory said it cannot provide any opinion on the similarity or dissimilarity of the voices in question.

The finding emerged during the hearing of a petition seeking a court-monitored investigation into the recordings, which purportedly relate to the ethnic unrest in Manipur last year.

A Bench comprising Justice Sanjay Kumar and Justice Alok Aradhe examined the matter on Monday.

After reviewing the sealed NFSL report, the Court ordered the parties to receive its final findings and scheduled the matter for further hearing on December 8.

“Four exhibits showed signs of modification and tampering. Justice Kumar read from the report, saying, “The clips are altered, do not constitute the original source recording, and are not scientifically fit for forensic voice comparison.”

The Bench added that it cannot offer any opinion on the similarity or dissimilarity between the speakers in question and the control clips.

The petition, filed by the Kuki Organisation for Human Rights Trust, had previously submitted a report from Truth Labs, a private forensic agency.

The report claimed that a 50-minute recording marked Y1 was unedited and matched the control voice sample with 93% probability. Justice Kumar noted that the petitioner would receive the NFSL report to respond formally.

“We will give you the report so you can respond to it,” he said.

The Court ordered the Registrar to provide the NFSL’s final report, dated October 10, 2025, to counsel for all parties.

Advocate Prashant Bhushan, representing the petitioner, emphasized that despite the recordings’ alleged significance, the government had not acted on them for over a year and a half.

Solicitor General Tushar Mehta, appearing for the Union Government, highlighted that the NFSL itself found evidence of tampering and advised against judicial intervention, noting that the state is currently peaceful.

Counsel for the Manipur government said he could not follow the conversations in the recordings, to which Bhushan responded that the NFSL had access to advanced tools to enhance audio clarity.

The Supreme Court first directed the Central Forensic Science Laboratory (CFSL) to examine the audio clips on February 3, 2025, and later sent them to NFSL in August 2025 for a comprehensive forensic analysis, including verifying edits and matching the voices with admitted samples.

The case continues, with the Court seeking to balance the need for forensic clarity and justice with the current peaceful situation in Manipur, listing the matter for further hearing on December 8.