Commenting on Prime Minister Narendra Modi's DNA remark, Bihar Chief Minister Nitish Kumar said it was inappropriate for a person holding such an important position to speak in such "tone and tenor".

"His (Narendra Modi) tone and tenor was unbecoming of a Prime Minister. I have been watching politics since 1969. In the past, prime ministers have never used such language against their opponents," Kumar said in an interview with Ashok Mishra, Hindustan Times reported.

While addressing a public meeting on Saturday in Muzaffarpur, Modi had targeted Kumar and said: "There seems to be some problem in his DNA because the DNA of democracy is not like that. In democracy, you give respect even to your political rivals".

Kumar said that Modi was "indecent" on his part of comment on his DNA because he belongs to the family of a freedom fighter. He further called it as an insult not only to him but also to the people of Bihar.

"My father was a freedom fighter. But they (BJP and RSS) had not participated in the freedom struggle. Only such people who have nothing to do with the freedom struggle can question others' DNA. It is indecent on his part and an insult to Bihar and its people," IANS quoted Kumar as saying.

"I am a Bihari and Modi has insulted and humiliated all Biharis by questioning my DNA and using such a language," Kumar had said last week.

Modi's DNA comment sparked controversy inviting criticism from the chief of JD(U)'s ally RJD, Lalu Prasad Yadav. Yadav too said Modi insulted Biharis by questioning Kumar's DNA.

A day after Modi targeted Kumar, BJP leader Sushil Kumar Modi too commented on his DNA. He "ridiculed' the Bihar CM for likening insult to his DNA with that of the people of Bihar.

"It is ridiculous that Nitish Kumar who has betrayal and arrogance in his DNA is trying to epitomize himself as Bihar," Sushil Modi said, and added that there is a huge difference between the DNA of the people of Bihar and that of the CM.