That's according to information seen by the BBC.

The evidence suggests that China's cotton crop, which makes up 1/5 of the world's total supply, could be far more dependent on forced labor than was previously thought.

Now, over the past few years, more than a million Vigurs are thought to have been detained in so called reeducation camps.

China denies claims of torture and carrying out forced sterilizations and abortions.

In response to the latest evidence, the Chinese government has told the BBC that claims of forced labor are entirely fabricated.

Our China correspondent John said Worth has this special investigation from Xinjiang, a region where foreign journalists are followed very closely On monitored Xin Jiang makes mountains of cotton 1/5 of the world's total and our investigation will only heighten concerns about this product.

Although the evidence wasn't easy to find on the way were turned back at checkpoints, Way stopped from filming questioned and following further behind is also following us.

This is one site we're trying to get to a giant reeducation camp.

But more recently, something else has Bean built next door, a textile factory Days after its completion, A large group of people could be seen being moved between the camp and the factory.

Wow, this is a factory here.

It's extraordinary.

From the ground, it's clear the factory and accommodation blocks are all now one single site plastered with Communist Party slogans.

But when we get out to film way are entitled to film in public, anywhere in China says these places air simply about creating jobs.

But everywhere we go, there's this extraordinary effort to stop is documenting any of us in Xinjiang.

A whole culture is under suspicion.

More than a million Uyghurs and other traditionally Muslim minorities are thought to have been swept into the camps.

Viewed by China has potential Islamist separatists that shot you.

But each year more than two million others are being gathered for something else.

Giant new factories and textile mills, hundreds of thumb, where they face strict controls on political indoctrination through the first thing our workers have to learn is to love the Communist Party, this factory boss says thing.

But now the BBC has seen evidence that shows we gers are also being sent on Mass into the cotton fields.

One day my family will disappear from this world.

Mahmoud, not Israel name, left Xinjiang three years ago, but his family still lives there on.

My mom told me like she's picking the cotton.

For the government officers, it's like over duty to do to do that work.

They will just go because they are so afraid off being taken toe jail or some somewhere else.

Newly uncovered documents show the scale 150,000 pickers sent toe one area, almost a Zeman E, again organized for another.

They're given ideological education and the lazy, the authorities say, are being taught the glories of work.

The evidence suggests that the rial intention here in Xinjiang is the dismantling of an entire culture and its rebuilding through the total control of people's families, their faith, their thoughts and on a massive scale across the fields and factories of this region in the work that they do.

In a written statement, the Chinese government said workers from all ethnic groups in Xinjiang choose their jobs according to free will and signed contracts in accordance with the law.

It said accusations of forced labor were completely fabricated, but the researcher who unearthed the documents believes they have major implications for the global fashion industry.

For the first time, we not only have evidence of week of forced labor and manufacturing in government making, we have evidence off a massive state sponsored forced labor scheme involving hundreds of thousands over half a million off, I think minorities and it's directly about the picking of cotton terms of global supply chains.

Now that's a game changer.

As we leave Xinjiang, we passed this prison camp complex thought to contain multiple factory buildings.

It's the first independent footage of this truly colossal site.

A final chilling reminder that here mass incarceration and mass labor, a closely connected John said.

Worth BBC News Xinjiang.