London: A British explorer who went missing on an expedition to search for a remote tribe in Papua new Guinea has been spotted, alive and well, and is awaiting medical evacuation, his close friend said.

Benedict Allen was dropped by helicopter into the remote jungle three weeks ago and has not been heard of since. He was hoping to reach the Yaifo, a tribe thought to be one of the last on earth to have no contact with the outside world.

British explorer Benedict Allen has been sighted after going missing in Papua New Guinea. Credit:Twitter

The author and TV presenter, who has made six TV series for the BBC, has no mobile phone or GPS device with him and was expected to begin his journey home at the weekend.

Sky News reported that Allen was expected back in Port Moresby on Sunday for a flight to Hong Kong, where he was due to give a speech to the Royal Geographic Society.