Transcript for Police in India say they are close to recovering the body of American missionary

isolated tribe buried him. ABC's Marci Gonzalez has the latest from Los Angeles. Good morning. Police say they sent planes and ships to get a better view. Of the area and narrow down where his body likely is. They're getting guidance on how to best move forward with what they describe as an ultra sensitive situation. Reporter: ABC news obtaining images of the handwritten pages of John CHAU's journal detailing his final days. The photos coming as police in India say they're closer to pinpointing where the body of the 26-year-old American missionary is buried. CHAU travelled to the remote island of nornt sentinel to convert trab members to christianity. He writes you might think I'm crazy, but I think it's worth it to declare Jesus to people. Authorities are trying to figure out how to retrieve his remains. Without putting rescuers or the tribe who has no immunity to modern diseases at risk. As far as I know the U.S. State department and everyone else is still gathering facts. It is difficult, but we're still gathering information about the possibility. Reporter: Authorities believe members of this tribe which has lived in isolation for 60,000 years shot him with arrows. Fishermen reported seeing his body being dragged and buried on the beach. CHAU reportedly knew traveling to the island was illegal bribing local fisher men to drop him off on shore. After describing in his journal his first contact with the islanders he wrote about the risk he faced returning. Writing to his family please do not be angry at him or god if I get killed. This was was his life mission. This was what god has called him to do which is to go and share the love of god with these people. With the holidays and I can't imagine how hard it is for his parents, his relatives and friends that this has happened. Seven people were arrested accused of helping CHAU get close to the island. Police say they're working with two of them to narrow down more details about his death. They still don't know how long

This transcript has been automatically generated and may not be 100% accurate.