Advani's blog 'Mahatma was perhaps not right' on Wednesday also said Sardar Vallabhbhai Patel's contributions have not been acknowledged.
"This book by Rajmohan Gandhi has effectively nailed the Congress party's slanderous campaign against the RSS in respect of Mahatmaji's assassination," Advani wrote.
The BJP leader said that Rajmohan Gandhi in his book on Patel quoted a letter dated Feb 27, 1948, written by Patel to Jawaharlal Nehru.
The letter said: "I have kept myself almost in daily touch with the progress of the investigation regarding Bapu's assassination case. I devote a large part of my evening to discussing with Sanjeevi (head of intelligence and inspector general of police, Delhi) the day's progress and giving instructions to him on any points that arise. All the accused have given long and detailed statements. It emerges clearly from these statements that the RSS was not involved in it at all."
Advani said that anyone who analyses history "readily feels that if Gandhiji had chosen Sardar Patel instead of Pandit Nehru to become free India's first prime minister, it is quite likely the history of those early years may have been quite different".
Advani wrote on his blog 'Mahatma was perhaps not right'
He also quoted Rajmohan Gandhi's book on Patel, saying "while acknowledgements are fulsome in the case of Nehru, and dutiful in the case of Gandhi, they are niggardly in the case of Patel".
"But the opinion of some that the Mahatma had been less than fair to Vallabhbhai was a factor in my decision to attempt to write the latter's life. If a wrong had been perpetrated, some reparation from one of the Mahatma's grandsons would be in order," the book said.
The BJP patriarch added: "For Rajmohan, Gandhiji's grandson, to say openly that Gandhiji had perhaps not been right in the decision he took about prime ministership, and, so merited some 'reparation' from one of his grandsons not only revealed his own greatness and magnanimity but also endorsed the general view that Sardar would have been a more appropriate choice."