Jesuit priest Stan Swamy, an accused in the Elgar Parishad-Maoist links case, has died, an official of a hospital where he was being treated informed the Bombay High Court on Monday.

Swamy, 84, died at 1.30 pm on Monday, Dr Ian D'Souza, director of the Holy Family Hospital in suburban Bandra, told the HC's division bench of Justices S S Shinde and N J Jamadar.

The tribal rights activist was admitted to the private hospital on May 29 from the Taloja prison following the HC's order on a petition filed by him, seeking medical attention as he was then suffering from COVID-19 and Parkinson's disease.

D'Souza told the court that Swamy suffered a cardiac arrest early Sunday morning following which he was put on ventilator support. He (Swamy) did not recover and passed away this afternoon, the official told the court.

The cause of the death is pulmonary infection, Parkinson's disease and post COVID-19 complications, he said.

Swamy's counsel Mihir Desai said there was negligence on part of the Taloja prison authorities, who failed to provide immediate medical attention to the Jesuit priest.

Swamy has been undergoing treatment at the Holy Family Hospital here, following a court order on May 28. The cost of his treatment at the private hospital is being borne by his associates and friends.

On Saturday, advocate Desai told a bench of Justices S S Shinde and N J Jamadar that Swamy's health was critical and that he was still in the hospital's intensive care unit (ICU).

The bench had then adjourned the hearing on Swamy's medical bail plea to Monday and extended his stay at the hospital till then.

Last week, Swamy also filed a fresh plea in the HC, challenging section 43D(5) of the Unlawful Activities Prevention Act (UAPA), that imposes stringent bars on the grant of bail to an accused charged under the Act.

On Monday, Desai said he will not be moving the HC for any urgent hearing on either the bail plea or the fresh plea challenging provisions of the UAPA.

"I don't have any morning updates on his (Swamy's) health. But, till late last night, he was on ventilator support," Desai said.

"So, the priority now is his medical treatment. Even if he is acquitted by the court tomorrow, what can happen? His health condition is such that he will continue being in the hospital," he said.

The senior lawyer also said he didn't have any complaints against the high court and the private hospital.

"The high court bench did all that was possible to secure the best medical treatment for him. And at the hospital, the best cardiologists and specialists are looking after him. Our only complaint is against the Taloja prison superintendent and against the NIA (the prosecuting agency in the case)," he said.

The National Human Rights Commission (NHRC) on Sunday issued a notice to the Maharashtra government in the wake of a complaint alleging serious health condition of the imprisoned activist.

In the notice sent through the state's chief secretary, the NHRC called upon him to ensure every possible effort is made to provide proper medical care and treatment to Swamy as part of life-saving measure and protection of his basic human rights.

The commission also called for a report in the light of the allegations made in the complaint, and the treatment record of the activist.

Swamy and his co-accused in the Elgar case have repeatedly complained of inadequate health facilities at the Taloja prison in neighbouring Navi Mumbai, where they were lodged as undertrials.

Through their pleas filed in the HC as well as oral and written statements made in the HC, they have complained several times of neglect on part of the Taloja prison authorities in ensuring medical aid, timely tests and maintaining hygiene and social distancing.

In May this year, Swamy told a vacation bench of the high court via video-conferencing that his health had consistently declined at the Taloja prison.

He had urged the HC to release him on interim bail at that time and said if things continued the way they were, he "would die soon".

Last week, the wives of activists Anand Teltumbde and Vernon Gonsalves, who are also accused in the Elgar Parishad-Maoist links case, moved the HC saying the Taloja prison superintendent had been withholding letters and communications to and from all the accused in the case following a magazine article published by Teltumbde in March this year.

On Monday, advocate Desai said the superintendent had reportedly been transferred out of the Taloja prison, though the reasons for his shifting were yet to be made public.

In the Elgar-Parishad case, Swamy and his co-accused have been charged by the National Investigation Agency (NIA) as being members of frontal organisations working on behalf of the banned CPI (Maoists).

Last month, the NIA had filed an affidavit before the HC opposing Swamy's bail plea. It had said there did not exist a "conclusive proof" of his medical ailments. It alleged that Swamy was a Maoist, who had hatched a conspiracy to create unrest in the country.

The Elgar Parishad case is related to inflammatory speeches made at a conclave held in Pune on December 31, 2017, which, the police claimed, triggered violence the next day near the Koregaon-Bhima war memorial located on the outskirts of the western Maharashtra city.

The police had claimed the conclave was organised by people with alleged Maoist links.

Swamy, who claims to be suffering from several ailments, including the Parkinson's disease, had moved the high court earlier this year through advocate Desai, seeking medical treatment and interim bail on health grounds.

He had tested positive for coronavirus at a private hospital last month and was subsequently shifted to the ICU.