MK Narayanan was one of the officials instrumental in the Indo-US nuclear deal.
Former NSA MK Narayanan on Tuesday asserted that "80 per cent of the claims" made in the book, ''The Accidental Prime Minister: The Making and Unmaking of Manmohan Singh'', were "false".
Slamming the author of the controversial book, Sanjay Baru, Mr Narayanan said the journalist and former media adviser to the then Prime Minister Manmohan Singh was "not a big player".
Mr Baru had written the book during the 2014 Lok Sabha elections to make money, alleged the the National Security Adviser (NSA), believed to be close to the former PM.
"It's a book full of lies. Eighty per cent of his claims are false. He was not a big player of the game (in the government). He was nobody,"
Mr Narayanan said in a session with the Bharat Chamber of Commerce.
He alleged that Mr Baru could not manage the media and ran away in 2008 as he had thought the Congress-led United Progressive Alliance (UPA) government would not return to power.
"The contents (of the book) are his own views," the former IPS officer added.
Mr Narayanan was one of the officials instrumental in the Indo-US nuclear deal, a major achievement of the Manmohan Singh government.
Mr Baru's book spawned a film on Singh's tenure in office that was released on January 11.