According to one popular version of events, Netaji Subhas Chandra Bose died in an air crash in Taiwan in 1945. But many of his relatives, friends and followers have disagreed with this narrative, forcing the Indian government to commission three different inquiries into the event between 1956 and 1999.
Last year, the Indian government refused to provide information on Netaji's reported death under the Right to Information Act. The possibility of obtaining closure to the mystery was again lost.
Such has been the controversial discourse that the reported death has been called 'India's Biggest Cover-Up' in a recent book.
Here are five things about the controversial reports of Netaji's death that you must know:
What the official Japanese version says about the fatal crash
When Netaji flew out of what's now Taiwan on August 18, 1945, after the defeat of Japan in World War II, the plane crashed while taking off and he was badly burnt. He died a few hours later in a local hospital and his body was cremated within two days. His ashes were taken to Tokyo and handed over to the Renkoji Temple where they remain to this day.
As Netaji's family and friends disagreed with this sequence of events, the British government set up an inquiry, which ultimately corroborated the Japanese account.
The crash: Questions which led to controversies
Even as a multitude of "what if" possibilities have been explored in conspiracy theories, there were a set of critical questions that remained unanswered regarding the supposed plane crash, as journalist Vir Sanghvi pointed out in an analysis.
"Most of Bose's lieutenants who had accompanied him on his travels were not allowed to get on the plane with him. They never saw a body. No photographs were taken of Bose after the crash. There are no photos of the body. And there is no death certificate. So it is possible to argue that the Japanese faked his death to allow him to escape the advancing British army," Sanghvi wrote.
The legend of the sadhu and the USSR connection
A few years after Netaji's disappearance, reports emerged that he had returned to India and lived in the disguise of a sadhu in north India.
Some reports even claimed that this sadhu was sighted at Jawaharlal Nehru's funeral, though no such claim could ever be substantiated.
Though the sadhu story was never proved, it resurfaced again when the Mujherjee Commission (1999-2005), led by Supreme Court judge M K Mukherjee, explored the possibility of Netaji living in the guise of a hermit in India. The report brought into light a sadhu named Gumnami Baba or Bhagwanji living in Uttar Pradesh.
The Mukherjee Commission's report, which questioned the claim that Netaji died in a plane crash, was, however, rejected by the government.
Another conspiracy theory which gathered steam was that Netaji went to the USSR post his reported plane crash. In the political climate of the World War II, he thought that Russia could be a safe haven.
What the CIA thought 19 years after the disappearance
In 1964, the CIA still believed that Bose was alive!
According to media reports, declassified documents showed that the Central Intelligence Agency was told in 1964 that Bose survived an air crash of 1945. The documents also showed that the US spy agency was not convinced of the veracity of the official Japanese version.
The reports said that in May 1946, a CIA agent wrote to the US secretary of state saying he had been told that "should (Bose) return to the country, trouble would result which would be extremely difficult to quell".
The CIA document said: "There now exists a strong possibility that Bose is leading a religious group undermining the current Nehru government."
PMO's refusal to share Netaji files
In December last year, the NDA government, in its response to an application under the RTI law by activist Subhash Chandra Agrawal, declined to declassify files related to Netaji's death and claimed such a move would prejudicially affect relations with foreign countries.
The PMO's "top secret" files on Netaji are believed to include documents on the Mukherjee Commission's report, on correspondences with and about Netaji's widow and daughter and the purported transfer of his ashes to India.