Mr Singh says his book is a 'purely academic exercise'
India's Hindu nationalist BJP has "dissociated" itself from a new book on Pakistan's founder Mohammed Ali Jinnah, written by a party leader.
Jaswant Singh's book, Jinnah-India, Partition, Independence says that Mr Jinnah has been "demonised in India".
The book also holds former PM Jawaharlal Nehru and the Congress party responsible for the partition of India.
Mr Jinnah is a controversial figure in India and considered the architect of the partition.
BJP chief Rajnath Singh said in a statement that the views expressed by Jaswant Singh in the book "do not represent the views of the party".
"In fact, the party completely dissociates itself from the contents of the book," he said.
Mr Singh said that Mr Jinnah had played an important role in the "division of India which led to a lot of dislocation and destabilisation of millions of people".
"It is too well known a fact - we cannot wish away this painful part of our history."
Mr Singh has said that his book is a "purely academic exercise, which should be read and understood". "My book is not an attempt to malign or glorify anyone," he told a TV channel.
None of the party leaders attended the launch of the book in the capital, Delhi, on Monday evening.
Mr Singh is the second leader of the BJP who has been criticised for his remarks on Mr Jinnah.
In 2005, party chief LK Advani offered to step down after he described Mr Jinnah as "secular", causing a furore in India.
Mr Jinnah is still widely blamed for the partition of India because of his drive for a Muslim homeland.