The Supreme Court was informed by the National Forensic Science University (NFSU), Gandhinagar, on November 3 that the audio recordings allegedly implicating former Manipur Chief Minister N. Biren Singh in the 2023 ethnic violence were found to be “tampered” and scientifically unfit for voice comparison, Live Law reported.

As a result, the premier forensic institution said it could not verify the authenticity of the speaker’s voice in the disputed clips.

The disclosure came in response to a petition filed by the Kuki Organisation for Human Rights (KOHUR) Trust, which has sought a court-monitored investigation into the alleged role of political leaders in the violence that engulfed Manipur in 2023.

In September 2024, the controversial tapes in public interest were accepted as evidence by the judicial commission set up by the Ministry of Home Affairs to probe the Manipur violence.

According to the final NFSU report dated October 10, 2025, and cited by Live Law, “four exhibits” submitted for analysis “showed signs of modification and tampering.”

The report concluded that the laboratory could not provide any opinion on whether the voice in the disputed recordings matched the control voice sample attributed to Biren Singh. The Hindu also reported the findings on Monday.

The NFSU’s conclusions sharply differ from an earlier analysis by the private forensic agency Truth Labs, which had claimed a 93% probability that one of the tapes matched Singh’s voice. Advocate Prashant Bhushan, appearing for the petitioners, mentioned this in court.

“We will give you the report so you can respond to it,” Justice Sanjay Kumar, part of the two-judge bench hearing the matter, told Bhushan. The bench, which also includes Justice Alok Aradhe, directed that the NFSU’s final report be made available to all counsels through the Registrar.

When Bhushan noted that Truth Labs had a credible record, Justice Kumar remarked, “We don’t know, because this [the NFSU] is supposed to be the premier forensic lab.”

Bhushan responded, “Yes, but it is a government lab. And your Lordships know that today when the government…” He added, “More than a year and half ago it was sent to the government and yet it remains uninvestigated by the government despite the very very damaging conversations and that,” Live Law reported.

In August, the apex court had questioned the Union government over delays in submitting the forensic report, pointing out that more than three months had passed since it was first sought.

Earlier, on August 19, a bench comprising Justices Sanjay Kumar and Satish Chandra Sharma clarified that the Central Forensic Science Laboratory (CFSL) had not been directed to establish the authenticity of the audio clips, but merely to test whether the voice samples matched.

Also read: SC Raps Forensic Lab for Mishandling Biren Singh Tape Case, Rejects Ex-CM’s Daughter’s Plea

An India Today NE report noted that the bench told Additional Solicitor General Aishwarya Bhati, “We don’t need the authenticity of the video to be established. The entire exercise seems to be misdirected. Only wishy-washy answers are being given. The CFSL is under the impression that we want to know if the video is authentic or not.”

During the hearing, the counsel representing the Manipur government said he was unable to follow the conversation in the recordings. Bhushan replied that forensic experts have advanced tools to enhance clarity.

The Supreme Court has directed that the NFSU’s report be shared with the parties in a sealed cover, with the next hearing scheduled for December 8.

Solicitor General Tushar Mehta, appearing for the Union government, told the bench that the situation in Manipur “is now peaceful” and cautioned against any step that could “meddle” with that peace.

The petitioners, however, maintained that judicial supervision was essential, arguing that the state machinery could not be expected to investigate allegations involving senior political figures impartially.