Expeditions down thundering river rapids and through pathless rainforests began in the Norfolk Fens for My Year With The Tribe presenter Will Millard

When Will Millard was a child he never wanted to leave the Norfolk fens.

Today he is one of the most adventurous travellers of his generation.

The television explorer has trekked through vast swathes of rainforest, survived encounters with poisonous snakes, hostile tribes and armed illegal diamond miners, almost died of malaria alone in the jungle and stumbled away from an expedition which went terribly wrong, close to starvation.

His new series My Year With The Tribe, on BBC2 on Sunday evenings, sees him return to West Papua and a tribe found living in tree houses and using stone tools just 40 years ago. As Will attempts to document an ancient hunter-gathering lifestyle he makes some disturbing discoveries and fears an ancient culture could disappear without a trace.

Will's love of adventure began in Upwell, near Wisbech. I first spoke to him in 2013, shortly after he'd returned from an epic raft adventure - for which he had trained on the River Ouse.

'I was a little boy who was outside all the time,' he said. 'Every single night I was out fishing, or on my bike, or on the river with friends.

'I loved being outside, but I was really scared of travel. I said to my mum and dad that I never wanted to leave Upwell.'

But by the time he left school (the village primary and then Wisbech Grammar) he was ready to make contact with the wider world, partly inspired by years of adventures with the local Scout group.

After spending a gap year and part of his sociology degree abroad Will developed a passion for rain forest. 'I just became addicted to it!' he said. A teaching job in West Papua enabled him to make, and then lead, expeditions into the vast, untracked interior.

On one journey, many days walk from any known village, Will became convinced he was being watched by an uncontacted tribe. 'I like the idea there are people still living on this planet that can express their choice to not make contact with the rest of us,' he said.

But when fellow explorer Benedict Allen got lost in Papua New Guinea last year, it brought back memories of the time he got lost and feared he would die on the same island.

Travelling with a schoolfriend from King's Lynn, he had hoped to discover ancient trade routes. Instead their guides stole most of their food before abandoning them. Starving, they realised they would have to abandon the expedition and hack their way out of the jungle. 'Planes have crashed here and never been seen again,' said Will. 'We lost two and a half stone each and just didn't know whether we would survive.'

Back in Britain Will began talking and writing about his adventures – and won a competition run by the Royal Geographical Society and the BBC, to help fund a 100 mile journey down the river border between Sierra Leone and Liberia in West Africa.

The soaring temperatures and humidity, and host of exotic animals, were a long way from the rivers of West Norfolk where Will had once built home-made rafts with friends, but he did part of his training on the Great Ouse at King's Lynn.

'I would practice with my pack-raft on the Ouse. When you get down to King's Lynn you get the tidal flow and it's not dissimilar. It's definitely the same colour!' said Will.

In Africa, alone in tiny pack-raft, carrying all his equipment, some of the most challenging moments involved plunging waterfalls and rapids, but the most terrifying of all came when he paddled around a corner to see a huge, illegal open-cast diamond mine.

'If you can't prove that you are who you say you are we will cut your throat and throw you in the bushes,' he was told.

Luckily he had a BBC identity tag. 'They turned out to be big fans of the BBC and listened to World Service every day!' said Will.

Then just three days from the end of his journey, where the great river flowed into the Atlantic, Will fell ill with malaria and, drifting in and out of consciousness, had to find a settlement where he could negotiate a chain of people to get him to the nearest hospital.

Will went on to make an award winning documentary for Radio 4. Earlier this year his television series about more placid waters of the River Wye was screened in Wales and his first book, the Old Man and the Sand Eel, was published this spring, telling the story of a fishing journey across Britain, inspired by childhood fishing expeditions in the Fens with his grandfather.

But he is still drawn to the rain forest and the lifestyles of people living in some of the most remote and isolated communities in world. His three part account of his experiences with the Korowai tribe of West Papua, My Year With The Tribe, continues on Sunday at 9pm on BBC2.