An American national has been allegedly killed by people belonging to the protected Sentinelese Tribes in the North Sentinel Island, sources said Wednesday, even as the US consulate said he was "missing".

A case of culpable homicide has been registered, and the fishermen who took John Allen Chau, 27, to the island have been arrested.

"We are aware of reports concerning a US citizen in the Andaman and Nicobar Islands. The welfare and safety of US citizens abroad is one of the highest priorities of the US Department of State," a US Consulate spokesperson said.

"When a US citizen is missing, we work closely with local authorities as they carry out their search efforts. Due to privacy considerations, we have no further comment," the spokesperson said.

According to a report published in a newspaper in Port Blair, Chau had visited the Andaman and Nicobar Islands five times earlier too.

He had expressed a desire to meet the Sentinelese Tribe, which is known to resist all contact with outsiders, often firing arrows at anyone who comes near.

According to the report, Chau had hired a fishing dinghy from the Chidiyatapu area and reached close to the island on November 16, from where he travelled in his own canoe. He had made a failed attempt on November 14 as well.

While his body had been spotted by fishermen, it has not been retrieved yet, the sources said.

Till recently, the North Sentinel Island was out of bounds for visitors. In a major step earlier this year, the government excluded this island and 28 others in the Union Territory from the Restricted Area Permit (RAP) regime till December 31, 2022.

The lifting of RAP meant that foreigners could be allowed to visit these islands without permission from the government.