Subhash Chandra Bose's family members were kept under surveillance between 1948 and 1968 by the Intelligence Bureau of India and intimated to the MI5.
The written letters of the Bose family were intercepted and copied by the IB officials. The IB shared with MI5 one such message between close Netaji aide AC Nambiar and nephew Amiya Nath Bose acquired through secret censorship and even sought more information on the subject.
The IB was directly reporting to the then Prime Minister of India, Jawaharlal Nehru. The surveillance results were shared with Britain's MI5 intelligence agency. The IB's recently declassified papers are now placed in National Archives and were accessed by Mail Today and India Today.