NEW DELHI: A top UN human rights official has deplored the death in custody of an 84-year-old Indian Christian priest who campaigned for the rights of tribal people and was denied bail after being detained under an anti-terrorism law. Father Stan Swamy was arrested last year on suspicion, which he denied, of ties to a banned radical leftist group that police accused of having instigated violence in Maharashtra state in 2018.

His death will revive criticism of the increasing use of the anti-terrorism statute under nationalist Prime Minister Narendra Modi's government. Opponents of the law say it is used to hound people critical of the government.

Swamy, who suffered from Parkinson's disease and also contracted COVID-19 while in prison, died in a Mumbai hospital on Monday. More than a dozen people gathered outside the St. Peter's Church in Mumbai, where his funeral service was being held, to protest over his death.

"The news from India today is devastating. Human Rights Defender & Jesuit priest Fr Stan Swamy has died in custody, nine months after his arrest on false charges of terrorism," said the U.N. special rapporteur for human rights defenders, Mary Lawlor.

"Jailing HRDs is inexcusable," she added in a Twitter post, referring to human rights defenders.

At a briefing in Geneva, UN human rights commission spokeswoman Liz Throssell said the agency had repeatedly urged India's government to protect a robust civil society. "We are very concerned with the way he was treated," she said, calling for the release of people detained without proper legal basis.

India's National Investigation Agency, which was pursuing the case against Swamy, did not respond to requests for comment. The federal home ministry and the foreign ministry also did not respond to a request for comment.