They are the biggest leak to date of the Chinese system of repression in the Xinjiang region: never-before-seen photos from inside internment camps, confidential official instructions and speeches by Chinese officials document the arbitrary and mass internment of Uyghurs in north-west China.
The documents, which SPIEGEL and Bayerischer Rundfunk analyzed together with twelve international media outlets, refute the Chinese government's claim that the hundreds of camps - which have been built in recent years - are vocational training centers whose inmates stayed there voluntarily .
For example, the data leak includes a previously unknown speech by the former party leader of the Xinjiang region in 2017, which stated that any prisoner who tried to escape even a few steps was to be "shooted".
According to estimates by the United Nations, around a million people were temporarily interned in Xinjiang, most of whom were Uyghurs, a Muslim minority in the People's Republic.
The Xinjiang Police Files include thousands of official photos of Uyghurs detained in camps and prisons.
So far, there have only been photos from Chinese internment camps that were taken by the authorities or at least with their approval or under supervision.
Now, for the first time, recordings that were apparently made by officials for internal use show a more unadulterated picture of what is happening behind the camp walls.
A number of inmates with injuries can be seen in the photos.
Where are the documents from?
The photos and documents, which are the largest leaked data on China's detention camps to date, were leaked to German anthropologist Adrian Zenz.
Zenz, who researches at the Victims of Communism Memorial Foundation in Washington, has been repeatedly provided with information on the mass internment of Uyghurs by whistleblowers.
According to the scientist, the Xinjiang Police Files came from an anonymous hacker who apparently penetrated the computer systems of Chinese security authorities.
According to Zenz, the source did not set any conditions, and there was no payment.
How was the authenticity of the documents checked?
DER SPIEGEL evaluated the Xinjiang Police Files together with a team of more than 30 journalists from 13 media outlets around the world – including the British BBC, »El País« in Spain, »Le Monde« in France and the Bavarian Broadcasting Corporation and checked for authenticity.
The photos were compared with satellite images, and metadata was read out and evaluated.
In addition, scientists from the Fraunhofer Institute for Secure Information Technology and the image analyst Hany Farid from the University of Berkeley independently confirmed the authenticity of the photos.
The Xinjiang Police Files include photos and names of thousands of people detained in two camps in Konasheher County in 2018.
The research team compared the lists with databases of detained or disappeared men and women from the Xinjiang region.
Reporters from SPIEGEL and the BBC met in Turkey and the Netherlands relatives of detained Uyghurs whose details appear in the Xinjiang Police Files.
They confirmed information from the leaked data.
The BBC also called more than 150 phone numbers listed in the files - several police officers and officers answered and confirmed their names and rank.
What does the Chinese government say about the research?
The leadership in Beijing has so far dismissed revelations about the mass and arbitrary internment of Uyghurs - and the associated human rights violations - as "fabricated lies and disinformation".
The Communist Party claims that the camps are training centers designed to alleviate poverty in the region.
Authorities also claim that some of the actions in Xinjiang were aimed at countering Uyghur extremists.
The international research team that evaluated the Xinjiang Police Files has confronted the government in Beijing and several Chinese embassies around the world with the results and asked for an opinion.
The request went unanswered.
What is the international community doing to protect the Uyghurs?
The European Union, the USA and Canada have regularly criticized China's treatment of the Uyghurs for years and have now also imposed sanctions on Chinese officials.
The US government even calls China's actions a “genocide”, and the Canadian and Dutch parliaments do the same.
At the same time, dozens of international countries – including North Korea, Syria and Saudi Arabia – have backed China.
On Monday, UN Human Rights Commissioner Michelle Bachelet went to China for the first time to investigate the allegations in Xinjiang on site.
For years, Bachelet had unsuccessfully demanded access to the Uyghur region.