Manipur Audio Tapes Tampered, No Conclusive Voice Match with Ex-CM Biren Singh: NFSL Tells Supreme Court

In a significant development filed before India’s apex court, the National Forensic Science Laboratory (NFSL), Gandhinagar, has reported that certain audio-clips submitted in relation to the ethnic violence in Manipur were tampered with and are scientifically unfit for voice-comparison. Consequently, the NFSL stated that it cannot offer any opinion on whether the voice in question belongs to the former Chief Minister of Manipur, N Biren Singh.

A Bench of the Supreme Court, comprising Justices Sanjay Kumar and Alok Aradhe, was hearing a petition brought by the Kuki Organisation for Human Rights Trust (KOHR) seeking a court-monitored investigation into audio recordings that allegedly implicate Singh in violent events of 2023.

Key Findings

The NFSL’s sealed-cover report indicates that four exhibits display signs of modification and tampering, and therefore “do not constitute the original source recording” and are “not scientifically fit for forensic voice comparison”.

As a result, the Bench recorded, “No opinion on similarity and dissimilarity of the speakers in question and the control clips can be offered.”

The NFSL’s final case-report (dated 10 October 2025) is to be given to both parties for their response. The next hearing has been scheduled for 8 December.

Context & Competing Reports

The petitioner, KOHR, had relied on a private forensic analysis by Truth Labs India Private Limited, which concluded that a 50-minute recording (marked Y1) was unedited and showed a 93 % probability that the voice matched Singh’s control sample.

Meanwhile, Solicitor General Tushar Mehta, representing the Union Government, informed the Court that the NFSL’s findings themselves point to tampering in the disputed recording. He also submitted that the Manipur situation is “now quite peaceful” and urged minimal interference.

The Court had earlier called for forensic analysis from the NFSL after noting deficiencies in a prior report by the Guwahati Forensic Sciences Laboratory, which did not clearly confirm whether the voice in the recordings belonged to Singh