A tranche of Chinese Communist Party documents leaked to the New York Times reveal inside information about Beijing’s crackdown on ethnic minorities, including how Xi Jinping, the Chinese president, told officials to show “absolutely no mercy”, the newspaper says.

The cache of 403 pages was leaked by a person the newspaper described as a “member of the Chinese political establishment”.

Reporter Austin Ramzy said that they provided the information in an attempt to “prevent party leaders, including Xi Jinping, from escaping culpability for the mass detentions.”

The leak provided further evidence that the brutal crackdown against Uighur Muslims is happening Xinjiang, a vast province in west China, despite the Chinese government's denials.

Many human rights groups consider it to be the most widespread and brutal human rights abuse campaign in the world today.

Over one million members of ethnic minorities, primarily Muslim Uighurs, have been detained in prisons or internment camps in Xinjiang in the past three years, which is officially referred to as a crackdown on terrorism by Beijing.