andaman island
This aerial photograph taken on Sept. 22, 2018 shows Boat Island in the Andaman Islands, a remote Indian archipelago in the Bay of Bengal. Getty Images/Hari Kumar

The body of John Allen Chau, the U.S. missionary killed by tribesmen in a remote North Sentinel Island in the Indian Ocean, is yet to be retrieved as authorities are struggling to figure out how to recover it. Chau was apparently shot by the North Sentinel islanders with arrows last week after he traveled to the restricted area.

Police said the members of the tribe buried his body on the beach, which is inaccessible to anyone other than the islanders. Seven people who helped him reach the island have been arrested.

"It's a difficult proposition," Dependera Pathak, director-general of police on India's Andaman and Nicobar Islands, where North Sentinel is located, said of the retrieval of the body. "We have to see what is possible, taking utmost care of the sensitivity of the group and the legal requirements."

Police are consulting anthropologists, tribal welfare experts and scholars to figure out a way to recover the body, he said.

Chau paid fishermen last week to take him near North Sentinel, using a kayak to paddle to shore and carrying gifts including a football and fish. His initial contacts with the Sentinelese -- a tiny tribe of hunter-gatherers -- had not gone well. One teenager shot an arrow at him, which pierced his waterproof Bible. However, he decided to return again despite the island visit being heavily restricted.

It was "a foolish adventure," P.C. Joshi, an anthropology professor at Delhi University who has studied the islands said, according to Fox News. "He invited that aggression... They are not immune to anything. A simple thing like flu can kill them," he said.

According to reports, the night before Chau returned for the last time to the Island, he was scared that his death might be imminent.

"I'm scared," the 26-year-old American from Washington wrote in his notes that he left with the fishermen. "Watching the sunset and it's beautiful - crying a bit . . . wondering if it will be the last sunset I see."

While details about how Chau died remains unclear, fishermen watched from the boat as tribesmen dragged the American's body along the beach and buried his remains. His cause of death cannot be determined until the body is recovered. After the fishermen realized Chau had been killed, they left for Port Blair, the capital of the island chain, Pathak said.

In an Instagram post, his family said it was mourning him as a "beloved son, brother, uncle and best friend to us." They said Chau "loved God, life, helping those in need, and had nothing but love for the Sentinelese people."

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