Shastri died in Tashkent, at 02:00 on the day after signing the Tashkent Declaration, reportedly due to a heart attack, but people allege conspiracy behind the death. He was the first Prime Minister of India to die overseas. He was eulogized as a national hero and the Vijay Ghat memorial established in his memory. Upon his death, Gulzarilal Nanda once again assumed the role of Acting Prime Minister until the Congress Parliamentary Party elected Indira Gandhi over Morarji Desai to officially succeed Shastri.Impact of
sudden death of
Shastri immediately after signing the Tashkent Pact with Pakistan raised many questions in the minds of Indian citizens. The Prime Minister of India going to Tashkent for a pact and never coming back has not been accepted easily by Indian citizens. His health was fit according to his doctor, R. N. Chugh, and he had no sign of heart trouble before.
After death of Shastri, his wife Lalita Shastri had alleged he was poisoned. An epic poetry book in Hindi titled Lalita Ke Aansoo, written by Krant M. L. Verma was published in 1978. In this book, the tragic story about the death of Shastri has been narrated by his wife Lalita Shastri. There are still serious doubts surrounding the nature of his death. His son, Sunil Shastri, asked the government to unravel the mystery behind the death of Lal Bahadur Shastri. Raising doubts about the dark blue spots and cut marks on the abdomen of the body of his father after his death in 1966, Sunil asked how the cut marks appeared if a post-mortem had not been conducted.When Shastri went to the USSR for the Tashkent talks, he wanted a promise from Ayub Khan that Pakistan would never use force in the future. But the talks did not proceed and followed by death of Shastri on the next day.The Indian Government released no information about his death, and the media then was kept silent. The possible existence of a conspiracy was covered in India by the Outlook magazine. A query was later posed by Anuj Dhar, author of CIA Eye on South Asia, under the Right to Information Actto declassify a document supposedly related to death of Shastri , but the Prime Minister Office refused to oblige, reportedly citing that this could lead to harming of foreign relations, cause disruption in the country and cause disruption in the country and cause breach of parliamentary privileges.Another RTI plea by Kuldip Nayar was also declined, as PMO cited exemption from disclosure on the plea. The home ministry is yet to respond to queries whether India conducted a post-mortem on Shastri, and if the government had investigated allegations of foul play. The Delhi Police in their reply to an RTI application said they do not have any record pertaining to death of Shastri. The Ministry of External Affairs has already said no post-mortem was conducted in the USSR. The Central Public Information Officer of Delhi Police in his reply dated 29 July said, "No such record related to the death of the former Prime Minister of India Lal Bahadur Shastri is available in this district... Hence the requisite information pertaining to New Delhi district may please be treated as nil." This has created more doubts.The PMO answered only two questions of the RTI application, saying it has only one classified document pertaining to the death of Shastri, which is exempted from disclosure under the RTI Act. It sent the rest of the questions to the Ministry of External Affairs and Home Ministry to answer. The MEA said the only document from the erstwhile Soviet Government is "the report of the Joint Medical Investigation conducted by a team comprising R. N. Chugh, Doctor in-Attendance to the PM and some Russian doctors" and added no post-mortem was conducted in the USSR. The Home Ministry referred the matter to Delhi Police and National Archives for the response pertaining to any post-mortem conducted on the body of Shastri in India. Sunil Shastri, son of the former Prime Minister, called the transferring of application as "absurd" and "silly joke". "He (Lal Bahadur Shastri) died as sitting Prime Minister. It sounds very silly that MHA is referring the matter of death of second Prime Minister of India to a district level police." He also demanded that "It should be looked into by highest authorities like President, Prime Minister and home minister."
Later, Gregory Douglas, a journalist who interviewed former CIA operative Robert Crowley over a period of 4 years, recorded their telephone conversations and published a transcription in a book titled Conversations with the Crow. In the book, Crowley claimed that the CIA was responsible for eliminating Homi Bhabha, an Indian nuclear scientist whose plane crashed into Alps, when he was going to attend a conference in Vienna; and Lal Bahadur Shastri. Crowley said that the USA was wary about the rigid stand of India
on nuclear policy and of then prime minister Lal Bahadur Shastri, who wanted to go ahead with nuclear tests. He also said that the agency was worried about collective domination by India and Russia over the region, for which a strong deterrent was required.