Sister Valsa John went to Jharkhand to work with tribal people Police in India's Jharkhand state are looking at the possible involvement of Maoist rebels in the murder of a nun who campaigned for tribal rights.
Sister Valsa John was killed after about 50 people broke into her home last week. Police say that Maoist pamphlets were left at the crime scene.
They said that rebels were finding it hard to infiltrate the area where the nun had considerable influence.
More than a dozen villagers have been detained in connection with the murder.
Initially, the police said they believed the Maoist pamphlets were left at the crime scene to mislead investigators.
But after interrogating the detained villagers, police say they believe that rebels were behind the murder.
"She was a major block in their [Maoists'] way," senior police officer Arun Oraon told the BBC Hndi's Salman Ravi.
"Therefore, the Maoists fanned all the resentment against her. They provoked the villagers to resort to such an extreme step," he said.
Sister John's brother, however, says she recently spoke of threats from a "mining mafia". There has been no word from mining officials.
Some reports said that Sister John had also angered a group of tribal people by going to the police to file a complaint after a local woman was allegedly raped. The tribesmen wanted the issue to be settled out of court.
Mr Oraon said the police were investigating all these angles.
Sister Valsa, originally from Kerala, was working with the Missionaries of Charity and had gone to Jharkhand to work with tribespeople.
Our correspondent says she later took up the cause of tribal people displaced by mining around Pakur, about 400km (250 miles) north-east of the state capital Ranchi.
The state government has ordered an inquiry into the incident.
(news source BBC News Service)