This dossier, accessed by The Sunday Express, was first opened during the British Raj and has a bewildering list of details — from his “known disguises” to his “special habits and associates.”

The last update in the dossier was in 1963, after the Chinese aggression when Basu was detained.

Marked as Number 35 in the dossier, Basu’s aliases are mentioned as: Basu, Jyoti, alias Bocha, alias Bakul.

His address is the “Baradi Baidyer Bazar in Dacca (East Pakistan)” and his physical attributes listed are: “Height 5 feet 4 inches; fair complexion; thin build; dark brown eyes; black hair; moles on right elbow-joint and back of left ear; oblong face.”

What was Basu’s “special habit”?

He “walks fast.”

Next to the heading, “Peculiarities,” there is a blank.

Only three individuals figure as his associates: Indrajit Gupta (CPI veteran and former Home Minister who died in 2001), Somnath Lahiri (only Communist member in the Constituent Assembly, died last year) and Bhabani Sen Gupta (writer and foreign policy analyst).

Sister Sudha Dutta is marked down as the only “relative.”

It’s on his early politics and his arrests that the dossier gives specific details:

* In 1938 he became a member and later Deputy Leader of the re-modelled Indian Student Secret Communist Group in Britain.

* He returned to India in 1940 and became a Secretary of the Bengal Provincial Railway Fraction of the CPI in 1942.

* Arrested under Section 30(1) of West Bengal Security Act on March 26, 1948, and was released on July 6, 1948, with restrictions imposed on his movements.

* Again arrested in Tatanagar on August 16, 1948, while going to Bombay but acquitted.

* In 1949, he went underground and worked vigorously for the Railway strike. He was arrested and detained on September 1, 1950, and was released December 14, 1950.

* For his protests in Tram and Bus Fare Enhancement Resistance movement, he was detained on July 7, 1953 , and released on July 25, 1953.

* Detained on February 27, 1954, and released on March 6, 1954.

* Began “vigorous movement over the food issue” and courted arrest on September 18, 1957. Discharged on September 26, 1957.

“He belongs to the China lobby of the party which upheld the cause of China in connection with the Sino-Indian border dispute. For his prejudicial activities following the Chinese aggression he was detained on November 21, 1962, and continues to be under detention in Dum Dum Central Jail ( November 1963).”

Arun Prakash Mukherjee, a retired IPS officer who is currently writing a book on his experiences with Jyoti Basu, Indrajit Gupta and other leaders, recalls how he raised the dossier issue with Basu in 1969 when he was the deputy Chief Minister and held the Home and Police portfolio.