Your own respectable journalist "Prem Shankar Jha" had admitted that he was arrested from nepal and later on was brought to india. While indian agencies had assigned a guy who looked quite similar to him.
And just look at him how he was confessing the crime! just tell me which sane terrorists will tell each and everything to other reporters (especially indian reporter). And moreover the point which mr moeed have raised is very crucial why his accent was different from ours. And secondly from this video one can easily observe that he was putting stress on his accent which clearly tells he was simply making up an accent. His tone was very unique, but which is obviously not gonna be unique for you guys.