An evangelist from India needs prayers from Christians worldwide.

The wife of 47-year-old K.A. Swamy made the appeal after her husband suffered brain haemorrhage and subsequently fell into a coma following his arrest and temporary detention for distributing Bibles and other Christian literature, the persecution watchdog World Watch Monitor (WWM) reported.

A group of angry Hindus dragged Swamy to a local police station earlier this month after catching him distributing Christian pamphlets near a Hindu temple in Hussain Sagar lake in Hyderabad, the capital city of the southern state of Telangana.

Swamy is one of the volunteers for Gideons International, a Christian organisation that distributes Bibles for free in various places worldwide.

Although the police released him after six hours of detention, the stress he endured took its toll as he suffered a brain haemorrhage on his way home and later fell into a coma. There has been no change in his condition since two weeks ago, according to his wife.

His brother-in-law said Swamy had been threatened by Hindu extremists before and taken to the police station for interrogation. "This time he just couldn't take it," Swamy's brother-in-law said.

India has risen to number 15, up from no. 17 last year, in the 2017 World Watch List of countries where Christians are most persecuted, according to Open Doors USA.

The Christian organisation rates the persecution level in India as "severe," noting that Hindu extremists' level of impunity has increased.

The Open Doors report states that Christians are now "regularly attacked by radical Hindus" as the "level of intolerance continues to increase."

It says former Hindus who converted to Christianity bear the brunt of persecution. "They are constantly under pressure to return to their old beliefs, and are often physically assaulted, sometimes killed," it states.

Last month, a local bishop noted that Christians are finding it difficult to live normal lives in India.

Auxiliary Bishop Theodore Mascarenhas of the city of Ranchi in Jharkhand state in eastern India said Christians, who comprise only 2.3 percent of the Indian population, are particularly most oppressed in northern India, adding that evangelisation efforts in that area have been impeded, the Navhind Times reported.

The bishop nevertheless took pride in how Christians in India are showing their determination to persevere "faithfully until the end" despite the many challenges facing them.