A British explorer's family fear for his safety after he went missing in a remote jungle in Papua New Guinea while searching for a lost tribe of headhunters for a BBC documentary, his agent has said.
Benedict Allen was dropped by helicopter in the jungle in the north-west of the country known as the Central Range three weeks ago and has not been heard from since, the Daily Telegraph reports.
The 57-year-old had been due back in the capital, Port Moresby, on Sunday to take a flight to Hong Kong to deliver a talk to the Royal Geographical Society on Tuesday.
He had written on Twitter and his website before his departure that he may not be heard from for some time, but his family now fear for his safety.
His agent, Joanna Sarsby, told the Daily Mail: "His wife Lenka has not heard from him. She is very worried. He would never miss something like the Hong Kong talk unless something had happened."
Allen, a father of three, had been attempting to track down the Yaifo tribe, which are among the few remaining tribes left on Earth not to have contact with the outside world.
Sarsby said that the Yaifo were "quite a scary bunch" and that it was "really odd" Allen had not returned on schedule.
He is a very experienced explorer, known for immersing himself among indigenous peoples. His daring expeditions include crossing the Gobi desert and Amazon basin. He once had to eat his dog to survive after becoming lost in the rainforest.
Allen said he had made the "first outside contact" with the Yaifo tribe 30 years ago and was returning "to create a brief record of their lives, if possible tracking down some of those... who'd remember me".
"No outsider has made the journey to visit them since the rather perilous journey I made as a young man three decades ago," he wrote on his website in September. "This would make them the remotest people in Papua New Guinea, and one of the last people on the entire planet who are out-of-contact with our interconnected world."
He said that, when he visited the tribe 30 years ago, he had been greeted "with a terrifying show of strength, an energetic dance featuring their bows and arrows".
"On this occasion who knows if the Yaifo will do the same, or run off, or be wearing jeans and T shirts traded eons ago from the old mission station. But of course I may not even made it there - even aged 26 it was a very hard hike up through rather treacherous terrain.
"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; together we managed to achieve the only recorded crossing of the Central Range. So, if this website or my Twitter account falls more than usually silent - I'm due back mid Nov - it's because I am still out there somewhere."
He said that "just like the good old days" he would not be taking a satellite phone, GPS or a travelling companion.
In a post on Twitter on October 11, Allen wrote: "Marching off to Heathrow. I may be some time (don't try to rescue me, please - where I'm going in PNG you won't ever find me you know...)"
A Foreign Office spokesman said: "Our staff are assisting the family of a British man who has been reported missing in Papua New Guinea, and are contacting the local authorities."
This article was originally on the Daily Telegraph and is reproduced with permission.