Tribal activist Father Stan Swamy, who was imprisoned in the Bhima Koregaon case, passed away on Monday ahead of his bail hearing in the Bombay High Court.
The 84-year-old had approached the Bombay High Court seeking bail on medical grounds.
The NIA had opposed his application for bail.
Following a HC order, Father Stan was transferred to a private hospital in May for treatment during the pendency of his bail plea. On Sunday night, he was put on ventilator support after his health deteriorated.
The NIA arrested Swamy on October 8 last year, in a case related to the violence which erupted at an event to mark 100 years of the Bhima-Koregaon battle on January 1 in 2018, leaving one dead and several others injured.