The video was broadcast by certain news channels. It also went viral on social media and was widely used to condemn the organisers of the controversial event in JNU campus.
Later, another set of news channels started broadcasting different version of the same video, questioning its authenticity.
"We got to know about the video showing the JNU student leader raising anti-India slogans and we also came across allegations that the video was doctored. So, we have sent it for forensic examination," sources said.
The police had registered the case of alleged sedition against Kumar and criminal conspiracy on the basis of a video clip which they had acquired from a Hindi news channel.
Jawaharlal Nehru University is caught in a row over an event on campus against the hanging of parliament attack convict Afzal Guru, where "anti-national" slogans were allegedly raised.
Kanhaiya Kumar is in judicial custody in a sedition case over the event.