When the men first sighted the beautiful baby antelope in the moonlight, it was past three o'clock in the morning. The creatures were only a few hours old and still wobbling about on their spindly little legs. Mothers and grandmothers nuzzled them protectively. A single male stood guard, sniffing the air tentatively for any signs of danger. It was a beautiful, heart-warming sight that could easily have been taken from a David Attenborough documentary - but for what happened next.
When the men first sighted the beautiful baby antelope in the moonlight, it was past three o'clock in the morning.
The creatures were only a few hours old and still wobbling about on their spindly little legs. Mothers and grandmothers nuzzled them protectively. A single male stood guard, sniffing the air tentatively for any signs of danger.
It was a beautiful, heart-warming sight that could easily have been taken from a David Attenborough documentary - but for what happened next.
A group of six men in a four-wheel-drive truck slowly approached the herd. A rough-looking man lifted an ageing automatic rifle to his eye, took aim and fired. A pregnant antelope dropped to her knees and began twitching violently.
The rest of the men in the truck threw back a green tarpaulin and switched on an enormous headlight to bathe the herd with a burning white light. The antelope froze with fright, making them easy targets.
In a matter of seconds, the entire herd was gunned down with assault rifles and machine guns. Dozens of antelope lay dead - slaughtered for one of high-fashion's most desirable 'items', the shahtoosh shawl, made from the wool of the chiru antelope.
Coveted by the super-rich and fashionistas alike, shahtoosh has a mystique like no other. Shahtoosh, which means 'king of wool' in Persian, is so fine, light and translucent that a shawl made from it will pass through a wedding ring.
It makes cashmere feel like horse-hair and the delicate astrakhan (made from foetal lambs) like an old woollen jumper. Napoleon gave a shahtoosh shawl to Josephine. Indian maharajas gave them to their concubines and Chinese emperors sent armies to plunder them.
Shahtoosh went out of fashion almost a decade ago, shortly after it became illegal and police around the world began to crack down on traders. But in certain circles in the UK, shahtoosh is once again becoming a must-have commodity, with no one knowing or caring where it comes from.
Consumers are fuelling a trade that is driving to extinction one of the most beautiful and exotic creatures in the world. It is also driving a parallel and equally illegal boom in poached tiger bones, drugs and arms.
"It's a disgusting trade," says Trevor Pickett, of Picketts, one of London's most exclusive leather and scarf boutiques.
"We get dealers coming in from time to time, but we always send them on their way. Even if it wasn't illegal, we still would not touch it."
Andy Fisher, head of the Metropolitan Police's Wildlife Crime Unit, says: "If there is a market for something, then someone will supply it.
"Twenty years ago shahtoosh was traded on a small scale by local communities. But once the fashion industry adopted it, the trade exploded and so did the poaching.
"It is important that people realise what they are supporting when they buy shahtoosh. They are fuelling the poaching of endangered species and supporting organised crime."
High in the mountains of Ladakh, on the border between Tibet and India, lie the most lucrative hunting grounds for the poachers. They slaughter the chiru with automatic weapons mounted on off-road vehicles.
Those creatures that escape the bullets are caught in vicious leghold traps. The animals may remain there in agony for days before a hunter arrives to dispatch them. Poachers who lack guns often pursue the animals by motorbike until they die of exhaustion.
Once the antelope are killed, their fleeces are torn from their bodies and a few ounces of wool plucked from their soft fleecy stomachs. Occasionally their horns are used in medicines. The rest of the body has no value except for the occasional meal for a poacher.
Attempts have been made to farm chiru, but shearing the antelope proved impossible as the shahtoosh has to be plucked directly out of the animals' skin to be usable. It is also far, far easier to gun the animals down than to tend them. This has led to a free-for-all slaughter on an astonishing scale.
Before shahtoosh became fashionable in the early 1990s, more than a million animals roamed the Tibetan plateau. Of these vast herds only about 75,000 antelope now remain, with an estimated 20,000 killed each year by poachers.
Shahtoosh is so light and valuable that it has become almost a parallel currency in the Himalayas and is used to pay for guns, drugs and other illegal wildlife products.
Thousands of pounds' worth can easily be hidden inside the lining of a jacket and smuggled over borders with only the slightest chance of being caught, and as such it has become a common 'currency' among crime gangs and terrorist groups, such as Kashmiri separatists.
In particular, wildlife experts say that it is a key part of a complicated transaction that involves tiger bones being smuggled into China, via Tibet, where they can fetch huge prices as a black market medicine.
In return, the smugglers are paid in shahtoosh to take back to India, where the market for the fine wool is booming.
When the raw wool is smuggled into India from Tibet it has a street value of around £500 a pound. Trafficking tiger bones one way and shahtoosh the other earns the smugglers profit margins of 600per cent or more.
As a result of this two-way trade, one tiger is killed in India every day. There are now only about 3,000 left in the whole of the sub-continent.
"Every shahtoosh shawl has the blood of a tiger on it," says Belinda Wright of the Wildlife Protection Society of India.
"Two species are being slaughtered for this shameless trade - the chiru and the tiger. Chirus are being killed in their thousands and the tiger pushed to the brink of extinction for the sake of fashion and the greed of a few ruthless wildlife criminals."
The wool is eventually smuggled into the Indian state of Jammu and Kashmir, where it is woven into fabric.
It is a highly-skilled process, as the fur fibres are only half an inch long and extremely difficult to handle.
The shawls are then adorned with the season's most fashionable new patterns ready for sale.
In a programme to be broadcast soon on the Animal Planet channel, undercover detective Steve Galster managed to track down a dealer to Dharamshala in northern India. He was selling the scarves for £500, a small fortune in India.
These scarves would have been trafficked into Britain, America and Europe, where they would have fetched up to £15,000. Weight for weight, that makes the shawls more valuable than cocaine or gold.
Even if smugglers are caught in the UK, the penalties for trading are pitifully low. One dealer was fined £1,500 for selling 138 shawls worth £350,000. That works out at less than £11 per shawl.
Small wonder, then, that shahtoosh has become a significant part of the booming £6billion illegal wildlife trade. The trade as a whole is now the thirdlargest illegal activity after drug smuggling and gun running.
In the UK, shahtoosh shawls are available if you have the money and the 'right' connections.
A TV reporter was recently offered shawls for £3,000 apiece in London. They are also available on the internet.
From time to time 'shahtoosh parties' are held where fashionistas meet to show off their shawls and buy the latest designs. Most will know full well where the wool for their scarves comes from, but they peddle a variety of lies so they appear less heartless.
They claim that the wool is gathered-from bushes that the antelope use as scratching posts, or is plucked from the down of the mythical 'toosh' bird. They will never admit that they know three young antelope must die so they can wear a single shawl.
The Metropolitan Police is aware of the parties, but has yet to make any arrests despite their best efforts. They are, after all, exclusive invitation-only events.
"Some people just want something that they think is 'better' than the next person and they have an awful lot of money to spend on such things,' says Andy Fisher of the Metropolitan Police.
"It does make you wonder what they're thinking of. There are enough exclusive, expensive items out there for them to buy. They do not have to drive a species to extinction."
The Indian and Chinese authorities have belatedly started taking the trade seriously and begun to clamp down on it - mostly, it has to be said, because of the trade's links with organised crime.
In August, the Indian police intercepted 57 shawls worth around £150,000 in Delhi. If convicted, the traffickers face up to seven years in jail.
The Chinese, too, have been stepping up their efforts to stop the slaughter with systematic antipoaching patrols. Given that the chiru antelope is the mascot for the 2008 Beijing Olympics, it would be very embarrassing for them if they failed to protect one of their country's national symbols.
The simple truth is that shahtoosh is so valuable that it is an almost irresistible source of money for poverty-stricken Tibetans. But the real driving force behind the trade is rich consumers in the developed world.
"You just have to look at who's buying the shawls,' says Robbie Marsland, UK director of the International Fund for Animal Welfare.
"Only the very rich can afford to buy these shawls. The demand from extravagant consumers has created a cruel and bloody trade, effectively signing a death sentence for these rare and beautiful animals."
• Crime Scene Wild with Steve Galster is broadcast on Mondays at 10pm on the Animal Planet channel.