NEW DELHI — A 24-year-old American YouTuber who was arrested after visiting an off-limits island in the Indian Ocean with hopes of establishing contact with a reclusive tribe was further detained in custody on Thursday.

Mykhailo Viktorovych Polyakov will next appear before a local court in Port Blair — the capital of India’s Andaman and Nicobar Islands — on April 29, police said.

Polyakov, from Scottsdale, Arizona, was arrested on March 31, two days after he set foot on the restricted territory of North Sentinel Island in a bid to meet people from the reclusive Sentinelese tribe.

He left a can of Diet Coke and a coconut as offering for the tribe this time after he failed to contact the Sentinelese. He shot a video of the island on his camera and collected some sand samples before returning to his boat.

“It may be claimed to be an adventure trip, but the fact is that there has been a violation of Indian laws. Outsiders meeting Sentinelese could endanger the tribe’s survival,” said a senior police officer, requesting anonymity as he isn’t authorized to speak about the case under investigation.

Polyakov is suspected of violating Indian laws that carry a possible sentence of up to five years in prison and a fine.

Visitors are banned from traveling within 3 miles (5 kilometers) of North Sentinel Island, whose population has been isolated from the rest of the world for thousands of years. The inhabitants use spears and bows and arrows to hunt the animals that roam the small, heavily forested island. Deeply suspicious of outsiders, they attack anyone who lands onto their beaches.

In 2018, an American missionary who landed illegally on the beach was killed by North Sentinelese Islanders who apparently shot him with arrows and then buried his body on the beach. In 2006, the Sentinelese killed two fishermen who had accidentally landed on the shore.

An official from the U.S. consulate visited Polyakov in jail earlier this week. “We take our commitment to assist U.S. citizens abroad seriously and are monitoring the situation,” the U.S. Embassy in New Delhi said in a statement, while declining to divulge further details due to privacy considerations.

Police said Polyakov had conducted detailed research on sea conditions, tides and accessibility to the island before starting his journey. He stayed on the beach for about an hour, blowing a whistle to attract attention but got no response from the islanders.

On his return he was spotted by local fishermen, who informed the authorities and Polyakov was arrested in Port Blair, an archipelago nearly 750 miles east of India’s mainland.