Indian police were forced to abandon an attempt over the weekend to recover the body of an American missionary after being stared down by members of the tribe that killed him.
Officers described seeing armed islanders standing on the shore as their boat approached North Sentinel Island, where 27-year-old John Allen Chau was killed while trying to tell them about Jesus.
The marine unit was around 400 metres from the shore but the police decided to turn around when it appeared the tribesmen were ready to fight, the Telegraph reports.
'They stared at us and we were looking at them,' Director General of Police Dependra Pathak was quoted as saying.
The tribe is one of the last remaining unpenetrated people groups in the world and is protected from outsiders by patrolling Indian Navy vessels.
The tribe is extremely hostile to outsiders, having previously killed two fishermen who drifted to their shores in 2006.
Chau was able to reach the island, in the Andaman Sea east of India, with the help of fishermen but kayaked the last stretch to the shore alone. In a journal written the day before his death, he described trying to offer the tribe gifts of fish and a football before being scared off when they attacked him with spears and stones.
In a dramatic account, he wrote that one spear went straight through a Bible he was holding in front of his chest. He also admitted being afraid of dying.
Despite his fears, he returned to the island the next day but was tragically killed.
The bid to retrieve his body is proving a challenging one. Mr Pathak said the fishermen had helped to map the general search area but the authorities have not spotted the body yet.
They are going to great lengths to avoid conflict with the preneolithic tribe and disrupt their way of life.
'The mission was done from a distance to avoid any potential conflict with the tribespeople as it's a sensitive zone,' he said.
'We are discussing with anthropologists and psychologists about the nature of the Sentinelese.'
He added: 'There are legal requirements as well which we need to keep in mind while carrying out the operation. We are also studying the 2006 case where two local fishermen were killed. The bodies were recovered then.'