Explorer Benedict Allen has gone missing after attempting to find an indigenous tribe in Papua New Guinea, it is reported.
The 57-year-old, who has previously recorded series for the BBC and written books on exploration, was on a journey to rediscover the Yaifo tribe.
In a post on his website before setting off titled “I may be some time”, Mr Allen said he was looking to meet with the tribe 30 years after discovering them for the first time.
He said: “No outsider has made the journey to visit them since the rather perilous journey I made as a young man three decades ago.
“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.”
A helicopter dropped Mr Allen off at Bisorio without a satellite phone, GPS or companion and he was due back in the country’s capital Port Moresby on Sunday to travel to Hong Kong.
His agent Joanna Sarsby told the Daily Mail his wife Lenka was “very worried”.
She added: “He is a highly experienced explorer, very clever and resourceful and adept at surviving in the most hostile places on Earth, and he would never give up. He may not be a young man any more but he is very fit.
“He was trying to reach the Yaifo people, a very remote and reclusive tribe – possibly headhunters, quite a scary bunch. Goodness knows what has happened.
“I just imagine he might have been taken ill or is lying injured somewhere, perhaps with a broken leg, and maybe being helped by locals. He never takes a phone with him – he believes in living like the locals. For him not to come back is really odd.”
Mr Allen’s friend, BBC security correspondent Frank Gardner, who travelled to Papua New Guinea with him twice last year, said: “I would say the chances are that Benedict is going to be fine, I hope those aren’t famous last words.
“Benedict always expected something like this. I had supper with him just before he left and he said ‘look, I’m quite certain I’ll probably be out of contact for quite some time and people shouldn’t worry about it’.”
The explorer’s sister, Katie Pestille, expressed concern for his safety.
She told BBC Radio Four’s Today programme: “He knows all about that survival stuff. It’s just what worries me is there are bad people in these jungles.
“You would think that they were totally empty but there are people in there. I mean, I know more about the Amazon, but there are loggers and drug dealers and all sorts of bad people.”