He was also the president of Akhil Bharatiya Hindu Mahasabha from 1943 to 1946.. He died in the custody of Jammu and Kashmir Police in 1953. He was provisionally diagnosed of a heart attack and shifted to a hospital but died a day later. In 2004, Atal Bihari Vajpayee had claimed that he was murdered in a "Nehru conspiracy". Since the Bharatiya Janata Party is the successor to the Bhartiya Jana Sangh, Mukherjee is also regarded as the founder of the Bharatiya Janata Party.