The body of an American evangelist killed by an ancient tribe on a forbidden island may never be recovered, experts have said.
John Allen Chau was reportedly killed in a "hail of arrows" after he visited North Sentinel Island to convert its protected people to Christianity – singing songs of worship and telling them "Jesus loves you".
Local fishermen saw tribespeople dragging his body around on the beach.
Authorities in India have not even tried to send police ashore to question the tribe, who have greeted outsiders with hostility for decades.
Meanwhile, tribal rights experts have warned it would be a "futile exercise" to try and retrieve Mr Chau's body.
Exposing the isolated group to people from the outside world could also be risky – amid concerns that 21st-century diseases as mild as the common cold could kill off the tribe.
Police have sent a boat near North Sentinel, which lies in the Indian Ocean, for a second time, with a statement adding: "Due precautions were taken by the team to ensure that this particularly vulnerable tribal group are not disturbed and distressed during this exercise."
The Sentinelese are believed to be the world's last pre-neolithic tribe.
Sophie Grig, who campaigns for isolated groups, said: "I don't believe there is any safe way to retrieve the body without putting both the Sentinelese and those attempting it at risk."
Pankaj Sekhsaria, who has written about tribes on other secluded islands, warned any attempt to recover Mr Chau could "create conflict with the community".
And Anup Kapoor, anthropology professor at the University of Delhi, said: "They have been killed and persecuted historically by the British and the Japanese. They hate anyone in uniform. If they see someone in uniform, they will kill him on the spot."
Nonetheless, police are liaising with experts about the best way to establish contact.
The Anthropological Survey of India has had previous rudimentary contact with the tribe – with one of its officials, C. Raghu, adding: "When we went there, nothing happened. Our seniors visited the island and they came back. It is because we are experts and know the pulse of the people.
"It's not just the risk of disease. You also have to think of how to handle yourself, what to say and what to share with them. To them, whoever gets there is from the outside, new world."
Mr Chau had tried to reach the Sentinelese several times, despite knowing it was illegal to go within three miles (five km) of the island. Seven people have been arrested on suspicion of helping him.
Notes written during his earlier attempts have revealed that a young boy on the island fired an arrow that hit his Bible.
Mr Chau wrote: "Why did a little kid have to shoot me today? His high-pitched voice still lingers in my head.
"I DON'T WANT TO DIE. Would it be wiser to leave and let someone else to continue. No I don't think so."
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In an Instagram post, his family said it was mourning him as a "beloved son, brother, uncle and best friend to us" – but added that they forgive his killers.
Officials said Mr Chau had visited the Andaman islands before – in 2015 and 2016.