Mookherjee is survived by his daughter, said a family member.
As a school boy, Mookherjee joined the freedom movement after he came in touch with Mahatma Gandhi. He was arrested in 1946 while observing the Rashid Ali Divas.
Later, he joined the all India Forward Bloc and fought the assembly elections twice unsuccessfully as its candidate. He also took part in the food movement of 1959 in West Bengal.
Beginning his journalistic career with Forward Bloc's Bengali mouthpiece Loksevak, Mookherjee at various times was associated with Lokmat, Ganabarta, Dainik Basumati, Bharatkatha, Satyajug, Bartamaan and Sambad Pratidin. He served as the chief reporter of Dainik Basumati.
His political analysis written under the nom de plume Krittivas Ojha were widely read.
He covered the Bangladesh liberation war and had close contacts with Bangabandhu Sheikh Mujibur Rahaman. His biography of Mujibur Rahaman "Ami Mujib bolchi" was critically acclaimed.
Body to be donated to hospital as per his wish.
He authored around 30 books, that included biographies of martyr Khudiram Bose, Forward Bloc leader Hemanta Kumar Basu and Communist Party of India-Marxist stalwart Promode Dasgupta.
Mookherjee was one of the founders of the Indian Journalists' Union. He played a leading role in it and served a number of terms as its general secretary and president, and toured a number of countries as part of media delegations.
His body was taken to the Forward Bloc state committee office where its state secretary Ashok Ghosh offered wreaths. Later, at the Press Club, journalists and CPI-M Politburo members Biman Bose and Surjya Kanta Mishra laid wreaths.
A wreath was also placed on behalf of West Bengal Chief Minister Mamata Banerjee.
Mookherjee had signed a pledge for posthumous body donation. The body would be donated to the NRS Medical College and Hospital as per his wishes, family sources said.