Aged just 23, he set off to fulfil a childhood dream by crossing the stretch of jungle between the Orinoco and Amazon deltas in South America, a journey that nearly cost him his life.

Fascinated by remote peoples, he underwent a tribal initiation ceremony in Papua New Guinea, and carries the scars on his torso to this day.

Then, after an abortive hunt for ape-men in Sumatra and further encounters with Aborigines in the bush of Australia, he returned to the Amazon Basin, partly out of curiosity and partly to lay a ghost that had dogged his footsteps ever since his first expedition.

Then, as much for companionship as anything else, Benedict picked up a mongrel to accompany him. As they swept along a remote river in a canoe, the dog bit into a sack of provisions, which spilled out and caused the craft to capsize.

Miles from anywhere, with only a minimal survival kit around his waist and all his supplies lost, Benedict was forced to walk for days through the jungle. Weak from lack of food, he felt somebody or something was following him, and sat down to wait. His pursuer turned out to be the dog, which, as the only thing between him and starvation, ended up as supper.

The dog saved Benedict's life - and gave him a reputation that was to follow him around the world. Mentioning the incident in his first book, Mad White Giant, Benedict provoked an outcry, spawning a field day for the tabloids and prodigious mail from animal lovers.

Talking to Benedict - gentle, modest, deeply thoughtful and effortlessly charming - in the drawing room of his cottage, it is difficult to imagine him upsetting anybody, or indeed doing anything more strenuous than gardening or going for a long walk.

'It's always struck me that explorers should go, leaving as much behind as possible, and learn instead from the local people,' said Benedict, now 36, who disdains maps and other unnecessary baggage.

'When I went back to South America, I knew it would take about seven months, crossing 3,600 miles [5,760 kilometres] from Ecuador and through the Mato Grosso. And I wanted to learn how to do it, to live in the rain forest, from the people there.' As teachers, Benedict sought out the Jaguar tribe, who lived deep in the forest and were reputed to be cannibals.

After making initial contact, Benedict was gradually accepted into the tribe, learning little by little and adapting their way of life. And he found a personal tutor in the shape of an eight-year-old girl called Lucy.

'Even though she had a Western name, she was extraordinarily at home in the jungle. She knew 20 different plants which could be used to disinfect cuts, and she'd show me new herbs which had other uses.

'I was amazed by her ability to walk through the forest and see it as a home, not a threat.' Finally, armed with what he had learned from Lucy and other members of the Jaguar tribe, Benedict set out through the jungle on his quest. But it was not long before disaster befell him.

'I was attacked by loggers. I was trying to cross a river but they grabbed my bag and ran off and I was left alone,' said Benedict.

'It was terribly scary. I sat myself down, besieged with all the old thoughts that nobody would know what happened to me or where I had died.

'Then I thought about Lucy, and how she saw the forest as a home. That's what picked me up. I thought if a child can survive, maybe I can. She had shown me how to eat the tips of ferns. It is mainly a psychological thing.' In time, Benedict managed to find his way again, and go on to complete his jungle odyssey. Benedict emerged from the jungle, and promptly turned his attention to Africa. By this time he had attracted the attention of the BBC, and initially against his will he had agreed to take a portable video camera on his expeditions.

'I'm still hung up on the idea that you should try to experience a place with as little cultural baggage as you can,' he said.

'I'm still suspicious of television - becoming involved in it has been the biggest change for me since I started travelling. I did one railway travelogue but it took a 10-man crew and we could only stay three weeks. We had to set up all the shots - it's very artificial.' So for his next African expedition Benedict travelled solo again, trekking from south to north right the way across the Namib Desert, the first time the journey had ever been completed.

'I had solar panels on the back of Nelson, the main camel, to recharge the video camera's batteries,' Benedict explained.

As well as the camera, BBC executives insisted Benedict carry a Global Positioning System so he could navigate by satellite if necessary ('I felt I was betraying my principles,' he said, peevishly), and the Namibian Government decreed he should take a revolver to guard against attack by lions.

But first there were three camels to train. 'At the beginning they let me ride them, but on the second day when I still hadn't gone away they started to resist as they knew I was up to something.

'After three weeks my body was covered with bruises and my knuckles were raw, but gradually I got them on my side.' More encumbered than usual, Benedict set out on the trek that was to last 3.5 months, from the Orange River on the South African border 1,500 kilometres due north to Angola.

'It was a wonderful privilege - even Namibians aren't allowed to do that. It was very exciting. We were a self-sufficient team, and the camels were working with me and it felt like they were the crew of a yacht and I was the skipper - you create your own world.' It was an inhospitable world, too, with supply dumps which Benedict had previously set up the only source of sustenance, the whitening bones of previous explorers in the sand to remind him of just how precarious his situation was, and the danger of attacks by lions.

'I was worried about what would happen when I got started and would be alone in the desert - would I crack up? But the amazing thing was once I was there I found it really encouraging.

'There was a tremendous amount of activity, snakes and beetles and things, and I kept coming across Bushman carvings from 3,000 years ago. I got the feeling of this place having been a home, despite it being an apparently hostile desert. I remember coming across the skeletons of three diamond prospectors and felt this was man's greatest ritual, and nature had reduced it to nothing.' Part of the Benedict's appeal is not just his sheer guts, but his refreshing genuine honesty and decency. He admits being terrified, and to his own helplessness at times. He slept with the revolver under his pillow in Namibia, but was worried he might shoot one of the camels, so left the chamber empty despite the danger from lions.

As for the future, Benedict sees himself continuing on his travels. 'English people seem to be drawn to desolate places, perhaps because we are overcrowded here,' he says. 'I'm happy at home, but I'm more content when I'm away. And yet, I need both. I'm a restless person by nature.'