As 64 files on Netaji Subhas Chandra Bose were made public today by the West Bengal government, his relatives demanded an investigation into alleged spying on the legendary freedom fighter and his family.


The newly declassified files prove that the Bose family was spied on by government after Netaji purportedly died in a plane crash in Taiwan, his grand-nephew Chandra Bose told NDTV.


"Why did they spy on my father, Amiya Bose? He was not Dawood Ibrahim! Yet they deployed 14 men from the intelligence branch to spy on him. Why should the Indian government spy on the families of an Indian revolutionary? I demand that PM (Narendra) Modi institute a probe," Bose said.


Hours before the files were made public this morning, it was "leaked" to the family that a crucial file was destroyed in 1972 when Siddharth Shankar Roy was Chief Minister of Bengal.


"The information is that the file relates to the disappearance angle of Netaji," Bose said.


Whether Netaji died in the 1945 crash, as was reported, has been questioned by his family and followers and has been an abiding mystery for 70 years.


His relatives say the surveillance by the government between 1948 and 1968 - Jawaharlal Nehru was prime minister for most of those years - proves that the revolutionary was alive along after he was presumed dead. Asked what he thought was the reason for the alleged snooping, Chandra Bose said: "One theory is that Nehru had fear psychosis about Subhas Bose, that he felt that if Netaji returned, he would be finished. But I feel there is no substance in Nehru's fear." Chief Minister Mamata Banerjee, who announced the decision to declassify the Netaji files recently, said it was unfortunate that so much remained a mystery about the iconic leader who fought for India's freedom.


"We made a beginning. The people should know the truth. Let the central government also declassify files (on Netaji)," Ms Banerji said.