JLN (Somebody referred to him as JLN combine) and global political powers had tried their best to locate Subhas Chandra Bose as they did not believe in the theory that he had died. They had officially however declared him death as they wanted to ensure that the general public did not get to know anything about the very high level global political conspiracy. The reasons were Geo political in nature. In the cold war era India was extremely vulnerable and the three big powers, Russia, China, and United States (and its agent Britain) had a constant watch over every move of India. None of them wanted a strong, resilient India and would have done everything possible to thwart its growth. They had many willing puppets who for their narrow selfish interests were hell bent in promoting the interests of these countries. There were several wars and revolutions across Asia. Communist and Nationalist forces across Asia were growing stronger. So in this situation where conspiracies were galore and countries were at the mercy of the big powers, if there was one person who was capable of upsetting all the plans, was Subhas Chandra Bose. India was an extremely important pawn in the global Geo politics against whom another pawn Pakistan could be played to fulfill the interests and the aspirations of the global powers. If Subhas Bose were alive he would be the only leader who would try to protect the interest of his nation above everything else. Neither Britain, nor America believed that Subhas had died as their intelligence reports show atleast until 1964 and they did everything possible to locate him with the help of an only too willing Government of India. They had hopes that if he was alive he would surely contact his family members, esp. his elder brothers. In India IB under Bholanath Mullick played a key role in this snooping saga.
This snooping story, as well as some other facts listed out in the metamorphosis section of HOME | netajisubhasbose, goes to prove that the Government of India, despite all their official positions, at the leadership level, did not believe that Netaji had died in an aircrash.