Last week's violent fracas at Delhi's Ramjas College has ignited, yet again, a nationwide debate on freedom of speech and what it means to be (anti) national.

The script of the current unrest seems similar to last year's Jawaharlal Nehru University controversy when a group of students was alleged to have raised anti-national slogans.

However, JNU student leader Kanhaiya Kumar raised no anti-India slogans for which he was charged with sedition last year, top officials investigating the case have revealed to India Today, citing forensic examination of voice samples.

Controversial slogans resonated through the JNU campus in February, 2016, sparking a national debate on freedom of expression and nationalism.

Bhim Sen Bassi was commissioner of the Delhi police when several students of the Jawaharlal Nehru University, including Kumar, were charged with sedition for alleged anti-India cries.

POLICE YET TO FILE CASE

But an India Today investigation has found police have yet to file a formal chargesheet in the case that involved charges as serious as sedition. Bassi and his successor Alok Verma have, in the meantime, moved on from the city's police force.

A senior special-cell officer, requesting anonymity, said, "We are trying to connect the lose ends and are in the process of filing a chargesheet." The officer added that it would be incorrect to say there is no evidence against accused in the case.

Top sources in the Delhi police's special cell, which is investigating the matter, have revealed they sent as many as 40 video samples of the controversial JNU event for forensic examination

Most of the footage, they said, have been found to be authentic.

Also read: If Afzal Guru is terrorist, so is Godse: Kanhaiya Kumar

UMAR KHALID MAY HAVE RAISED ANTI-INDIA CRIES

Anti-India sloganeering did ring through the JNU campus that day, but Kumar's voice has tested negative in the forensic tests, highly-placed special-cell sources revealed.

Kumar, the investigators said, had reached the scene after a clash broke out between JNU students and Akhil Bharatiya Vidyarthi Parishad activists.

But lab examinations have identified nine students as possible slogan-shouters, including Umar Khalid and Anirban Bhattacharya, special-cell sources said.

Most of the other slogan shouters were Kashmiri students from several universities, Jamia Millia Islamia and the Aligarh Muslim University included, according to special-cell officials.

But no FIR has since been lodged against the Kashmiri suspects, they said.

Also read: Ramjas violence: Campus politics turning colleges into battlegrounds, hurting academic freedom?

KANHAIYA: HAVE ALWAYS MAINTAINED MY INNOCENCE

India Today spoke to Kanhaiya Kumar, who said he has not seen this report, but added that he has always maintained that he has been wrongly implicated. "I was always sure that truth will come out... and conspiracy against JNU will also revealed," he said.

He went on to question if those who attacked him when he was brought to court would be booked and also asked if the BJP leaders who spoke against him would apologise.

On the matter of Khalid and Anirban, Kumar said, "Let court decide who is anti national and who should be punished... but this case and event of last February can't be used by the ruling party at their convenience to fool people and defame educational institutions."

Watch video: Kanhaiya Kumar raised no anti-India slogans in JNU, says lab report

(With inputs from Ankit Tyagi)