An independent and unofficial body set up by a prominent British barrister to assess evidence on China's alleged rights abuses against the Uighur people has concluded that the Chinese government has committed genocide and crimes against humanity.

The Uyghur Tribunal, made up of lawyers, academics and businesspeople, does not have any Government backing or powers to sanction or punish China. But its organisers hope the process of publicly laying out evidence will compel international action to tackle alleged abuses against the Uighurs, a largely Muslim ethnic group.

The tribunal chairman, Sir Geoffrey Nice, said the group was satisfied that forced birth control and sterilisation policies targeting Uighurs in China's far western Xinjiang province were intended to reduce the group's population. The abuse was part of comprehensive policies directly linked to President Xi Jinping and the highest levels of the Chinese government, he said.

The Chinese Embassy in London did not immediately respond to requests for comment. In Beijing, the Foreign Ministry spokesman, Wang Wenbin, said that "the so-called forced labour and genocide in Xinjiang are entirely vicious rumours".

Mr Wang was responding to a question about a law passed on Wednesday by the US House of Representatives to ban imports from Xinjiang over forced labour concerns. Mr Wang accused the US of using Xinjiang-related issues to "spread rumours under the guise of human rights and engage in political manipulation and economic bullying".

The Uyghur Tribunal concluded that it was beyond doubt that crimes against humanity were committed, including the torture and rape of scores of people held in vast detention centres.

"On the basis of evidence heard in public, the tribunal is satisfied beyond reasonable doubt that the People's Republic of China, by the imposition of measures to prevent births intended to destroy a significant part of the Uighurs in Xinjiang as such, has committed genocide," said Sir Geoffrey, a senior lawyer who led the prosecution of ex-Serbian President Slobodan Milosevic and has worked with the International Criminal Court.

He said President Xi and other senior officials "bear primary responsibility" for what has occurred in Xinjiang.

"This vast apparatus of state repression could not exist if a plan was not authorised at the highest levels," he said.

An estimated one million people or more - most of them Uighurs - have been confined in re-education camps in Xinjiang in recent years, according to researchers.

The hearings were the latest attempt to hold China accountable for alleged rights abuses against the Uighurs and other predominantly Muslim and ethnic Turkic minorities.

Around 30 witnesses and experts gave evidence to a series of public hearings in central London earlier this year, alleging torture, rape and beatings by authorities while in state detention centres in Xinjiang province.

The hearings also reviewed evidence, including leaked Chinese government documents, detailing other policies including systematic forced birth control, the separation of young children from their families, forced labour and the destruction of mosques.

The US government has declared that Beijing's policies against the Uighurs amounted to genocide and crimes against humanity. Legislatures in Britain, Belgium, the Netherlands and Canada have done the same.