An American preacher who kayaked to a remote Indian island populated by a tribe known for shooting at outsiders with bows and arrows has been killed, police said.

Key points: Mr Chau went back to the island a second time after locals fired an arrow at him

Mr Chau went back to the island a second time after locals fired an arrow at him His family said he worked as a missionary and "had nothing but love for the Sentinelese people"

His family said he worked as a missionary and "had nothing but love for the Sentinelese people" The tribespeople killed two Indian fishermen in 2006 when their boat drifted ashore

Dependera Pathak, director-general of police on India's Andaman and Nicobar Islands, said seven fishermen have been arrested for helping the American reach North Sentinel Island.

The Sentinelese people, believed to be the last pre-Neolithic tribe in the world, are resistant to outsiders and often attack anyone who comes near, and visits to the island are heavily restricted by the Government.

Mr Pathak identified the American as John Allen Chau and said he told a hotel he was 26 years old.

Mr Chau was apparently shot and killed by arrows, but the cause of death cannot be confirmed until his body is recovered, Mr Pathak told The Associated Press.

"It was a case of misdirected adventure," Mr Pathak said.

Mr Chau's family published a statement on his Instagram page saying they forgave those who killed him.

"We recently learned from an unconfirmed report that John Allen Chau was reportedly killed in India while reaching out to members of the Sentinelese Tribe," it says.

"Words can't express the sadness we have experienced about this report.

"… he was a Christian missionary, a wilderness EMT, an international soccer coach and a mountaineer.

"He loved God, helping those in need and had nothing but love for the Sentinelese people.

"We forgive those reportedly responsible for his death.

"He ventured out on his own free will and his local contacts need not be persecuted for his own actions."

In the wake of the 2004 tsunami this member of the Sentinelese tribe was photographed firing arrows at a helicopter. ( Supplied: Indian Coastguard/Survival International )

One police source told Reuters that Mr Chau had visited the Andaman and Nicobar islands in the past.

Police have learned he had a strong desire to meet the Sentinelese and preach on the island, the source added.

Police have approached anthropologists with contacts on the island in an effort to visit and recover the body, Mr Pathak said.

He said Mr Chau arrived in the area on October 16 and stayed in a hotel while he prepared to travel to the island.

It was not his first time in the region: Mr Chau had visited the Andaman and Nicobar Islands in 2015 and 2016, Mr Pathak said.

North Sentinel is in the Andaman Islands at the intersection of the Bay of Bengal and Andaman Sea.

Chau had strong desire to preach on the island: source

Mr Chau (right) was shot at with an arrow on the first day he visited the island, but he returned a second time. ( AP: Sarah Prince )

Mr Chau organised his visit to the island through a friend who hired seven fishermen for $450 to take him there on a boat, which also towed his kayak, Mr Pathak said.

Mr Chau went ashore in his kayak on November 15 and sent the boat with the fishermen out to sea to avoid detection, Mr Pathak said.

He interacted with some of the tribespeople, offering gifts such as a football and fish. But the tribespeople became angry and shot an arrow at him, hitting a book he was carrying, Mr Pathak said.

After his kayak was damaged, Mr Chau swam back to the fishermen's boat, which was waiting at a prearranged location.

He spent the night writing about his experiences on pages that he then gave the fishermen, Mr Pathak said.

The Sentinelese stand guard on an island beach. ( Supplied: Christian Caron )

Mr Chau set out again to meet the tribespeople on November 16.

What happened then isn't known. But on the morning of the following day, the waiting fishermen watched from a distance as the tribesmen dragged Mr Chau's body.

The fishermen left for Port Blair, the capital of the Andaman and Nicobar Islands, where they broke the news to Mr Chau's friend, who in turn notified his family, Mr Pathak said.

He said the family got in touch with Indian police and US consular officials.

Police charged the seven fishermen with endangering the life of the American by taking him to a prohibited area, Mr Pathak said.

'Fear of outsiders is very understandable'

Kathleen Hosie, spokeswoman for the US Consulate in Chennai, the capital of India's southern Tamil Nadu state, said she was aware of reports concerning an American in the islands but could not comment further due to privacy considerations.

Survival International, an organisation that works for the rights of tribal people, said the killing of the American should prompt Indian authorities to properly protect the lands of the Sentinelese and other Andaman tribes.

"The British colonial occupation of the Andaman Islands decimated the tribes living there, wiping out thousands of tribespeople, and only a fraction of the original population now survives," Stephen Corry, the group's director, said in a statement.

"So the Sentinelese fear of outsiders is very understandable."

Tribespeople killed two Indian fishermen in 2006 when their boat broke loose and drifted onto the shore. ( AP: Gautam Singh )

Shiv Viswanathan, a social scientist and a professor at Jindal Global Law School, said North Sentinel Island was a protected area and not open to tourists.

"The exact population of the tribe is not known, but it is declining. The Government has to protect them," Mr Viswanathan said.

Poachers are known to fish illegally in the waters around the island, catching turtles and diving for lobsters and sea cucumbers.

Tribespeople killed two Indian fishermen in 2006 when their boat broke loose and drifted onto the shore.

An Indian Coast Guard helicopter sent to retrieve the bodies was repelled by a volley of arrows from the community.

AP/Reuters