He also said that the recent arrest of Dawood's arch-rival Chhota Rajan may not help much in this regard.
"We can't say it's because of (help by Pakistan's spy agency) ISI or because of the lack of political will of the country (India). If he is still out of our clutches, it's because he is under the patronage of enemy country. And it's not a cakewalk to bring such a fugitive don back in such cases," said Kumar, without naming Pakistan where Dawood is suspected to be hiding.
Kumar added that the Indian government had made all possible efforts to bring Dawood back, and one day it would succeed.
The book is in the news with Kumar's disclosure that at one point in the 1990s Dawood wanted to surrender.
More From This Section
"I had three telephonic conversations with Dawood in 1994 when I was probing the 1993 serial blasts in CBI, and one conversation in 2013 during the my last days in Delhi.
"I don't claim that I would have got Dawood, or had my
lead been utilised better then we would have got him. I got an opening into the case and I worked upon it like any investigating police officer does," said Kumar.
To a question whether the recent arrest of Chhota Rajan would lead to a breakthrough in getting Dawood, Kumar said we should not have too much hope.
"Of course Chhota Rajan is a storehouse of underworld information, but it (the information) all is historical, (from) before 1993. They have been on the run and hiding from each other. So I don't think Rajan could be having some pinpointing information to nail Dawood," he said.
"I have written scripts for Hindi movies and serials. I am not new to the writing world. I know how to sequence the events and make them interesting," said Kumar.
The chapter in his book on the Memon family (many members of which were involved in the 1993 blasts) was his favourite as it had a lot of human element, he said.
The retired IPS officer, who is presently working as an adviser to the BCCI's anti-corruption unit, said legalising the cricket betting won't help much in ridding the game of corruption.