"Dossa was admitted to the jail ward of the hospital at 3 am," Hospital dean TP Lahane told PTI.
Dossa (lodged in Arthur Road jail) complained of chest pain and had uncontrolled hypertension, diabetes and infection, he said.
Yesterday, the CBI had sought capital punishment for Dossa, arguing that his role in the blasts was "more severe" than that of hanged convict Yakub Memon.
The CBI said Dossa was one of the "brains" behind the conspiracy and that his degree of responsibility towards the commission of the crime was the highest.
As many as 257 people were killed in the co-ordinated blasts that ripped through the city on March 12, 1993.
The court had acquitted another accused Abdul Quayyum of all charges.
The trial of the seven accused Abu Salem, Mustafa Dossa, Karimullah Khan, Firoz Abdul Rashid Khan, Riyaz Siddiqui, Tahir Merchant and Abdul Quayyum was separated from the main case as they were arrested at the time of conclusion of the main trial.
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