An explorer who lives in Bristol has gone missing after attempting to find an indigenous tribe in Papua New Guinea.
Benedict Allen was on a journey to rediscover the Yaifo tribe 30 years after he encountered them for the first time.
Allen, 57, has previously made programmes for the BBC and written books about exploration.
He tweets before he left saying, "I may be some time... don't try to rescue me, please."
A helicopter dropped him off three weeks ago - Allen chose to travel without a satellite phone, GPS or companion.
He was due back in the country's captial Port Moresby on Sunday to travel to Hong Kong but he didn't show up.