“Benedict looks forward to being reunited with his family and friends but will need some time to get back to full health,’’ the agency said in a statement. “He would like to send thanks for all the kind messages he has received.”

Mr. Allen had traveled to Papua New Guinea in hopes of reconnecting with the Yaifo, an indigenous people he met three decades ago in the remote Central Range of Papua New Guinea. He is believed to be the only Westerner to have made contact with the group.

In a blog post on his website before the trip, Mr. Allen described plans to hire a helicopter to drop him off at an abandoned mission station before gathering a group of local guides to help him.

He reflected on the difficulty of the journey and speculated that he might not be able to reach the Yaifo. It is unclear if he did encounter the community during his journey.

“Even aged 26 it was a very hard hike up through rather treacherous terrain,” he wrote. “Nor do I have an obvious means of returning to the Outside World, which is somewhat worrying, especially at my advanced age. Either I must paddle down river for a week or so — or enlist the help of the Yaifo, as I did last time.”