An Indian Christian was beaten to death this week after marrying another Indian Christian of a higher caste. 

Kevin Joseph, 26, a member of the socially poor Dalit caste, was murdered in a so-called 'honour killing' after he married Neenu Chacko, 20, who is an upper caste Syrian Christian.

Joseph was dragged from his house in the Kottayam district of India's southern state of Kerala on Tuesday. His body was found two days later in a nearby ditch.

Several members of Neenu's family have been arrested in connection with the attack, including her father and brother, Sanu Chacko, who left his job in Dubai on Saturday requesting emergency leave after his sister's wedding, according to the Khaleej Times.

Others in custody include Ishan Ismail, Neenu's cousin from her mother's side, and Niyas, 23, of Idamon, Kollam district, and Riyas, 26, according to Gulf News.

Two police officers are also in custody and have been suspended from duty, the Times of India reported, after Neenu said she told police of the kidnapping but they refused to respond. Instead they told her they were too busy arranging security for a visit by Pinaryi Vijayan, chief minister of Kerala.

'Had the police acted in time, a life could have been saved and criminals could have been arrested promptly,' Lathika Subhash, leader of the women's wing of the opposition Congress party, told a protest gathering, according to the National Catholic Reporter.

The murder has reopened a fraught debate about caste in Kerala state where upper-caste Christians, commonly called Syrian Christians, who claim to be descended from the priestly Brahmin caste of Hindu converted by St Thomas the Apostle in AD52, reject lower-caste Dalit Christians.

Kerala has a reputation for being particularly religiously diverse among India's state and Christians make up aroud 18 per cent of the population.

Syrian Christians form an influential majority among Kerala's 6.14million Christians whereas Dalits make up just 2.6 per cent.