The Liberation Tigers of Tamil Eelam (LTTE) had a 'mole' in 10 Janpath, and former prime minister Rajiv Gandhi's assassination was part of a conspiracy "hatched by several influential people in faraway places", says former home secretary of India R D Pradhan.

"Someone inside 10 Janpath provided crucial information to the mole," says Pradhan in his recently released book, My Years with Rajiv and Sonia, but he does not identify the 'mole'.

"I know for sure that Sonia Gandhi, who was away in Amethi virtually throughout the 1991 Lok Sabha election campaign, feels the same way," he claims in the 311-page book.

Gandhi was the opposition leader when he was blown up at an election rally site near Chennai by a woman suicide bomber of the LTTE on May 21, 1991.

The LTTE denied any involvement, but Indian investigators claimed the Tamil Tigers assassinated Gandhi to avenge the earlier deployment of the Indian Army in Sri Lanka's northeast.

Pradhan, who joined Rajiv Gandhi's team later, said, "On the basis of hindsight, one must admit that in the entire security planning in Delhi, the possibility of the LTTE making an attempt on the life of RG (Rajiv Gandhi) had been overlooked".

He says he once saw some Sri Lankans seated outside the 10 Janpath office of Vincent George, a long-time aide to the Gandhis.

"Obviously they had a contact at 10 Janpath who could arrange secret meetings with RG that not many knew of. I certainly did not," he says.

"Wasn't it the governor's responsibility to go into the whole security matter thoroughly? I have my doubts whether he applied his mind to the complexities involved," he says.

"He was the only one who could have stopped Rajiv Gandhi from visiting Sriperumbudur (the assassination spot) that night even after RG had landed at the Madras (Chennai) airport," says Pradhan. (With input from NDTV)