Poison arrows, knives, spears, clubs, axes, rocks — all of them have been waved very angrily.

Over the years, the message from the natives of the tiny island of North Sentinel in the Bay of Bengal could not have been clearer.

‘Keep away. Go home. Buzz off. Visitors not welcome. We want to be alone.’

Of course they do. The Sentinelese are one of a very few remaining ‘uncontacted peoples’ in the world and they are determined to keep it that way. Which means we know tantalisingly little about their language, their culture, their belief system or even how many of them there are.

But what we do know is that they have lived happily and largely healthily on their tiny, lush, mangrove-swamped 20-square-mile island for at least 30,000 years.

A Sentinelese man aims with his bow and arrow at an Indian Coast Guard helicopter as it flies over the island for a survey of the damage caused by the tsunami in 2004

During which time, they have feasted on wild pig, clams, berries and honey, engaged in energetic communal sex sessions on the beach and repelled pretty much every visitor (well-meaning or threatening) with a flurry of poison arrows and razor sharp machetes.

So it wasn’t such a surprise last weekend when John Allen Chau, a 26-year-old American Christian missionary-cum-thrill-seeking explorer who visited the island was felled by a poison arrow and then dragged round the white sand beaches by a piece of twine until he was dead.

Apparently Chau, a graduate of the evangelical Oral Roberts University, Oklahoma, who had previously declared visiting North Sentinel as his ‘must-do adventure’, had decided his life’s calling was converting the Sentinelese to Christianity.

Poor well-intentioned Chau. Of course, his death is an utter tragedy — a young life cut off in such an horrific and courageous way. He continued walking into the arrows as they fired, so intent was he on delivering his message from God.

And from all accounts he was a wonderful human being — ‘kind’, ‘big-hearted’ and ‘wonderful fun’.

The Sentinelese tribe has attacked almost everyone who has entered their territory. Pictured, the tribes people are seen wielding arrows on the island

But he shouldn’t have been there. Under Indian law, it is illegal for anyone to be within five nautical miles of the islands and, since last year, even filming the natives in the Andaman Islands — which include North Sentinel — has been illegal.

This is partly to protect visitors such as Chau, from the natives’ deadly tendencies.

But more importantly, it is to ensure the continued survival of the world’s last pre-neolithic tribe. A people, so isolated, so apart from, so unexposed to modern life that they are unlikely to have any resistance common illnesses such as flu, measles or even a cold.

As Sophie Grig, a senior researcher with Survival International, put it: ‘This is one of the most vulnerable tribes on the planet. He could be passing on diseases that could literally wipe them all out.’

Which as well as being a disaster for them, would be an anthropological catastrophe. Because the Sentinelese are the only surviving direct descendants of the first humans in Asia. More than 75,000 years ago they made their way from Africa to the Middle East, Burma and India.

John Allen Chau (pictured) was killed by arrows shot by protected tribesmen living on a remote Indian island after he arrived there in a bid to convert them to Christianity

Eventually, they reached the Andaman Islands. Some moved on, but others stayed on North Sentinel, drawn by the lush mangrove jungles, perfect white sandy beaches and a natural bounty so rich and easy to plunder there was no need to cultivate the land. The men hunted turtle, pigs and fish with spears, bows and arrows tipped with bone and hardwood.

The women gathered tubers, coconuts berries and clams and caught fish in homemade nets.

In the summer they collected honey, smearing their bodies with a special bee-repellent leaf paste.

All went naked (but for a few leaves, fibre strings and ornaments) and lived in huts in small family-based groups.

And that’s how they still live 30,000 years on, protected by the sea and their own latent aggression from modernisation, gadgets, plastic, stress and other humans.

The first documented contact with the tribe was made over 1,000 years ago by Chinese and Arabian explorers who were driven back with a barrage of arrows and described the natives as being three feet tall with human bodies and bird beaks. Pretty much every attempt to visit them since has ended in disaster.

The North Sentinel island is out of bounds even to the Indian navy in a bid to protect its reclusive inhabitants who number only about 150

When Marco Polo encountered the islands in the 13th century, he wrote: ‘They are a most violent and cruel generation who seem to eat everybody they catch.’ And, in 1563, a sailor, Master Caesar Frederick, warned: ‘If any ship, by ill fortune, stop at these islands, no one comes back alive.’

So for a long time, even when the rest of the Andaman and nearby Nicobar islands were colonised by the British in 1850 and turned into a penal colony, the Sentinelese were left alone to hunt, eat and generally make merry in their fecund island paradise.

Until 1880, when a British colonial expedition led by Maurice Vidal Portman landed with a squad of armed police, kidnapped an entire family and whisked them off to Port Blair in the Andaman Islands. The adults died immediately and a red-faced Portman hastily returned the four children with gifts.

For nearly a century after that, the islanders were left largely to their own devices.

Until, in 1970, a group of anthropologists approached the island, notebooks and cameras at the ready, and were peppered with arrows and then treated to an energetic beach sex show, described by one observer as a ‘sort of community mating . . . a frenzied dance of desire’.

The Sentinelese attracted international attention in the wake of the 2004 Asian tsunami, when a member of the tribe was photographed on a beach, firing arrows at a helicopter (pictured)

Four years later, there was another invasion attempt — this time the visitors were laden with offerings of a miniature plastic car, a live pig and a selection of aluminium pots.

The response? Yet another volley of poison arrows.

Occasionally, instead of firing weapons, the men wave their penises very angrily and, on rare occasions, would accept the odd coconut before opening fire. But the message has never changed.

‘Please leave us alone. We don’t want to be friends.’

Their decision to resist contact with the outside world is an intelligent one. They are frequently referred to as Stone Age or primitive, but from the little the ouside world has been allowed to learn, we know they are anything but.

For while they have reportedly forgotten how to make fire — they keep multiple fires burning at all times so as not to be caught out — and have no way of counting above two, their botanical, zoological and medicinal knowledge is astounding, albeit unconventional.

They apparently believe that edible plants are protected by good spirits and poisonous plants are favoured by evil.

Chau took a boat ride with the fishermen before venturing alone in a canoe to North Sentinel Island (pictured, a file photo shows tribesmen on the island)

Astonishingly, all the Sentinelese are thought to have survived the tsunami of Boxing Day 2004 in which 250,000 people perished. It is thought that, like many animals, they felt the earthquake, knew a monstrous wave was on its way and shimmied up the trees taking their precious fire with them.

And when the coast guard helicopter circled a few days later to see how they had fared, they peppered it with arrows until the pilot left declaring them ‘fighting fit’. No one knows the exact population, but it is thought to be in decline.

A 2011 count, from a safe distance, spotted 15 people. A census 10 years earlier estimated the population at 39.

The world was once full of ‘individuated’ cultures — indigenous island or jungle societies with their own languages and customs — like the Sentinelese.

Today there are just 100 groups of people scattered across the world — including the Yanomami in northern Brazil; the Ayoreo-Totobiegosode in Bolivia; and, until the last member died in 2011, the Andaman Islands’ Bo tribe — who know nothing of our world and do their utmost to keep theirs a mystery.

Chau hired a fishing dinghy and, aided by the fishermen, reached the vicinity of the island on November 16, before transferring to a canoe (pictured, a canoe he used in October)

But however unwelcoming they are, visitors keep coming.

Chau sounds like a bright and lovely young man. He claimed to have been ‘fascinated’ by the people of North Sentinel and had researched them.

Of course he knew of the danger he faced, if not the danger from his germs to the islanders. He must have known about the Panamanian freighter that ran aground near the island in 1981 and how the had been crew attacked by ‘wild men’.

And he’d have certainly heard of the two Indian fishermen macheted to death in 2006 after their boat accidentally drifted onto the white sandy beach while they were drunk on palm oil brew.

He even wrote a letter to his parents before he left, saying: ‘I think it’s worth it to declare Jesus to these people. Please do not be angry at them or at God if I get killed.’

He’d visited several times before the fateful trip last week — taking scissors, safety pins and a football as gifts. In return they rained arrows down on him and damaged his canoe.

He knew they didn’t want him, that visiting again was akin to entering a tiger enclosure. ‘I have been so nice to them, why are they so angry and aggressive’ he wrote in his diary.

The Indian government adopts what it calls a ‘hands off, eyes on’ policy for the tribe, which means officials moor boats nearby, to check on welfare from a safe distance.

While the seven fishermen who transported Chau and his canoe to within the exclusion zone — and watched while he was killed — have all been arrested, there is no question anyone on the island will be bothered by the authorities.

Let’s hope other reckless souls learn from poor Chau’s death. Because the survival of the Sentinelese depends on it.