An American tourist has been arrested after allegedly traveling to a remote island in the Bay of Bengal and attempting to contact one of the world’s most isolated tribes.

Mykhailo Viktorovych Polyakov, 24, made the illegal voyage to North Sentinel Island, home to the enigmatic Sentinelese tribe, on March 29, Indian police told CNN.

North Sentinel Island is a land mass roughly the size of Manhattan in the Andaman and Nicobar archipelago, about 1200km from the Indian mainland.

Visiting the island is prohibited by Indian law to maintain the Sentinelese way of life and protect them from modern illnesses, from which they lack immunity.

While Polyakov successfully reached the island, he does not appear to have made contact with the Sentinelese tribe, Jitendra Kumar Meena, head of the Andaman and Nicobar Police’s Criminal Investigations Department told CNN.

He was spotted by a local fisherman on his way back and arrested two days later, Meena said. Police seized an inflatable boat and motor from Polyakov.

He has not yet been charged with any offenses.

A spokesperson for the US State Department said “we are aware of reports of the detention of a US citizen in India” in a statement to CNN but could not comment further on the case.

It is not clear if Polyakov has retained a lawyer.

The Sentinelese have only made contact with the modern world a handful of times and have been known to vigorously reject outsiders.

Because the Sentinelese are so reclusive, it is difficult to know how many there are – estimates range from dozens to hundreds.

Previous encounters with the tribe have proved fatal. In 2018, American missionary John Allen Chau was reportedly killed by tribespeople after he arrived on North Sentinel Island, hoping to convert the local people to Christianity.

Polyakov is “lucky he did not make contact otherwise he would have met the same fate,” Meena said.

Caroline Pearce, Director of Survival International, a nonprofit dedicated to the protection of isolated tribal groups, called Polyakov’s alleged actions “reckless and idiotic.”

“This person’s actions not only endangered his own life, they put the lives of the entire Sentinelese tribe at risk,” Pearce said in a statement.

“It’s very well known by now that uncontacted peoples have no immunity to common outside diseases like flu or measles, which could completely wipe them out,” she added.

Polyakov planned his trip well in advance, visiting the Andaman islands twice before travelling to North Sentinel on his third visit, allegedly setting off from a beach about 40km away in South Andaman, Meena said.

“As per what he has revealed in the investigation so far, he said he is keen on adventures.

He said he had left some soft drink bottles there for the tribe but we haven’t found anything so far,” Meena said.

Police have seized Polyakov’s phone and GoPro, as well as a bottle of sand he allegedly collected from the island.

A special investigation team is carrying out a search of the island from afar, on boats using binoculars, despite choppy waters the last couple of days, Meena said.

World’s ‘most isolated’ tribe

There are more than 100 uncontacted tribes around the world, mainly in the Amazon rainforest, but the Sentinelese are “the most isolated Indigenous people in the world,” according to Survival International.

Most of what is known about them comes from boats moored more than an arrow’s distance from the shore and from rare past encounters with authorities.

The Sentinelese hunt in the rainforest and fish in the coastal waters using spears, bows and arrows, as well as homemade narrow outrigger canoes, according to Survival International.

They are thought to live in three groups in both large communal huts and more informal shelters on the beach.

First contact with the Sentinelese tribe was made by the British in the late 1800s, when, despite their attempts to hide, six individuals from the tribe were captured and taken to the main island of the Andaman Island archipelago.

An Indian law from 1956 bans outsiders from traveling to North Sentinel and other islands in the archipelago home to Indigenous groups.

Except for a brief, friendly interaction in the early 1990s, the Sentinelese have fiercely resisted contact with outsiders, even after disaster.

In 2004, following the Asian tsunami that devastated the Andaman chain, a member of the tribe was photographed on a beach on the island, firing arrows at a helicopter sent to check on their welfare.

Two years later, members of the tribe killed two poachers who had been illegally fishing in the waters surrounding North Sentinel Island after their boat drifted ashore, according to Survival International.

Pearce, of Survival International, said India – which has built up military infrastructure on the Andaman and Nicobar Islands in recent years in case of a confrontation with China – has a “legal responsibility” to protect the Sentinelese people from missionaries, social media influencers, illegal fishers or anyone else.

There have been other encounters with uncontacted tribes in recent years.

In February, a young man from an isolated Indigenous tribe in Brazil made brief contact with the outside world before returning to the Amazon rainforest.

In 2024, Survival International published rare images of the uncontacted Mashco Piro tribe in the remote Peruvian Amazon, reporting that the tribe was trying to evade loggers.