New Delhi: In a new twist to the mysterious disappearance of Netaji Subhas Chandra Bose, it has now been revealed that the Jawaharlal Nehru government spied on the relatives of the nationalist for nearly two decades.

According to Mail Today, two recently declassified Intelligence Bureau files, which are now in the National Archives, reveal unprecedented surveillance on the kin of Bose between 1948 and 1968.

Notably, Nehru served as the PM from 1947 until his death in office in 1964.

As per the report, the IB spied on the two Bose family homes in Calcutta: 1 Woodburn Park and 38/2 Elgin Road, and reported directly to Nehru.

The agency intercepted, copied letters written by family members of Bose and tracked their visits within country and abroad.

However, the reasons why they were asked to report on the family’s movements are not entirely clear.

The IB mainly tracked Sarat Chandra Bose's sons and Netaji’s nephew siblings - Sisir Kumar Bose and Amiya Nath Bose. The duo also wrote several letters to their aunt Emily Schenkl, Netaji’s wife, in Austria.

The revelation comes a day after the Calcutta High Court directed the central government to give its reasons for declining to declassify secret files on Netaji Subhas Chandra Bose.

A host of Netaji's descendants, enthusiasts, historians and organisations have been campaigning for declassification of secret files claimed to be in the possession of the central and West Bengal governments.

Calling Bose one of his favourite icons, Urban Development Minister M Venkaiah Naidu said the news that he was spied upon is shocking and truth must come out. Congress leader PC Chacko, however, said that there was no enmity between Bose and Pandit ji. “I think this is wrong interpretation of history”, added Chacko.

Commenting on the report, Aam Aadmi Party leader Ashutosh said he was "pained and shocked" to know that Bose’s family was being spied upon.