The Left parties on Monday called out the inhuman treatment meted out to activist Stan Swamy, who passed away at a Mumbai hospital after being in custody since last year following his arrest under the anti-terror law, in the Elgar Parishad case.

The 84-year-old priest-activist died on Monday, in the middle of his fight for bail on health grounds.

The Jesuit priest had been on ventilator support since Sunday, when his health worsened drastically. He was being treated at the Holy Family Hospital in Mumbai following a court order on May 28.

"Deeply pained and outraged at the death of Father Stan Swamy. A jesuit priest & social activist he tirelessly helped the marginalised. Draconian UAPA custody, inhuman treatment since October 2020 with no charge established. Accountability must be fixed for this murder in custody," CPI(M) general secretary Sitaram Yechury tweeted.

The CPI, in a statement, alleged that Swamy was denied medical treatment and demanded that those responsible for his death be arrested.

The party demands the arrest of all those responsible for his death and proper punishment for the inhuman treatment meted out to him. The people at large take his death as institutional murder. The 84-year-old Jesuit priest from Jharkhand was actively mobilising tribals in the area and fighting for their welfare

His death raises several questions regarding the judiciary, treatment in custody, denial of medical facilities, torture in custody... The party demands arrest of all those responsible for foisting false cases on him, his continued detention and inhuman treatment. They should be made accountable for his death and given proper punishment, the statement said.

The party calls upon the people to express their anger in protest and to fight for the fundamental rights guaranteed under the constitution, it said.

The Left party also demanded the release of all those jailed in the Bhima Koregaon case.

CPI(ML) general secretary Dipankar Bhattacharya called Swamy's death an institutional murder .

An ailing octogenarian human rights activist arrested on false charges under UAPA, his bail applications denied repeatedly, passes away in jail. Is the court now going to grant him posthumous bail? Let India rise in unison to condemn the brazen institutional murder of Stan Swamy, he said.

In a statement, the CPIM said the activist was denied treatment for his various ailments, including the debilitating Parkinson's.

"It needs to be underlined that it is only after a campaign was conducted by various human rights and disability rights organisations that even a sipper to drink liquids was made available to him in jail.

"The numerous appeals made to shift him out of the overcrowded Taloja jail that had seen a huge rise in Covid cases went unheeded. His appeals for bail and being sent home to were rejected. Thanks to the Bombay High Court's intervention he was admitted to a private hospital when his condition started deteriorating after he was infected with Covid. But it was too late to prevent his death in custody," the party said.

The party also demanded that all those jailed in the Bhima Koregaon case and other detenues under politically motivated cases, misusing draconian laws like UAPA, sedition, among others, be released forthwith.