China has committed genocide against the Uyghur people in Xinjiang, an unofficial UK-based tribunal has found.
The Uyghur Tribunal cited birth control and sterilisation measures allegedly carried out by the state against the Uyghurs as the primary reason for reaching its conclusion on Thursday.
Sir Geoffrey Nice, a prominent British barrister who chaired the tribunal hearings, said its panel was satisfied China had carried out "a deliberate, systematic and concerted policy" to bring about "long-term reduction of Uyghur and other ethnic minority populations". He added that the panel believed senior officials including the Chinese president Xi Jinping bore "primary responsibility" for the abuses against Muslim minorities in the Xinjiang region.
The tribunal's panel was made up of lawyers and academics. Its findings have no legal force and are not binding on ministers, but its organisers said at the outset they intended to add to the body of evidence around the allegations against China and reach an independent conclusion on the question of genocide.
The Chinese government denies all accusations of human rights abuses in Xinjiang. Responding to the tribunal's ruling on Thursday, a spokesman told the BBC the body was a "pseudo tribunal" and a "political tool used by a few anti-China elements to deceive and mislead the public".
Reading the tribunal's judgement, Sir Geoffrey said there was "no evidence of mass killings" in Xinjiang, but he said that the alleged efforts to prevent births amounted to genocidal intent. The panel also said it had found evidence of crimes against humanity, torture, and sexual violence against the Uyghur people.
Speaking to the BBC after the judgment, Sir Iain Duncan Smith, the former Conservative Party leader and co-chair of the Inter-Parliamentary Alliance on China, said it was time for the UK government to accuse China of genocide.
"The British government said the evidence needed to be assessed by a competent court, well it doesn't get more competent than this," he said.
"The government now needs to stop messing around. The genocide taking place in Xinjiang has got to dominate our relationship with China."
Conservative MP Nus Ghani called the conclusion of the tribunal "groundbreaking".
"This tribunal was set up to the highest legal standards and the evidence that that was put forward today shows that there is enough proof beyond reasonable doubt that there was an intent to commit genocide," she told the BBC.
"What is particularly troubling is the evidence that this genocide is in particular targeted at women, and focused on preventing births."
The Chinese state has been accused of crimes against humanity and genocide in Xinjiang, a large region in the country's north-west which is home to the Uyghurs and other minority Muslim groups.
Experts say that at least a million Uyghurs and other Muslims have been detained in the region and held in extra-judicial camps or sent to prisons. Former detainees and residents of Xinjiang have made allegations of torture, forced sterilisation and sexual abuse.
The Uyghur Tribunal heard from more than 70 witnesses over two sets of hearings in London in June and September, including former detainees and experts. Among the witnesses was the Uyghur linguist Abduweli Ayup, who testified about the harassment of his family in Xinjiang and the 15-month sentence imposed on him in his absence for inciting terrorism - a common allegation levelled by the Chinese state against Uyghurs.
Mr Ayup told the BBC the finding of genocide was "very encouraging".
"I was sentenced by the Chinese government, now I hope after this ruling someone can sentence them. Many Uyghurs have been sent to prison only for being Uyghur, now it is time their oppressors are also sentenced," he said.
The issue of whether China's alleged abuses amount to a genocide has divided the international community. The US government has accused China of a genocide against the Uyghurs, and the parliaments of the UK, Canada, the Netherlands, and Lithuania have passed resolutions making the same declaration.
But the UK government has declined to accuse China of genocide. Prime Minister Boris Johnson has argued that genocide is a specific term with legal force that should only be determined by a criminal court.
The case for genocide is based on reports that China is taking steps to erase the culture of the Uyghurs and assimilate or diminish the population through programmes of forced relocation and birth control.
In a report published in April, the US-based charity Human Rights Watch concluded that China was responsible for crimes against humanity in Xinjiang - but stopped short of calling the state's actions a genocide.
Amnesty International reached the same conclusion in its own report.
The Uyghur Tribunal was established by Sir Geoffrey at the urging of the World Uyghur Congress, a global activist group. The president of the WUC, Dolkun Isa, told the BBC the tribunal's judgment represented a "historic day" for the Uyghur people.
"Now there is no excuse for the international community to continue its silence on the Uyghur genocide," he said. "It is the legal obligation of all countries who signed the 1948 genocide convention to take legal action."
Reading the judgment on Thursday, Sir Geoffrey said the tribunal had formed in part because no international criminal court had taken up an investigation into the alleged abuses in Xinjiang.
The International Criminal Court announced in December last year that it would not investigate the allegations because China, as a non-member, was outside of its jurisdiction.
Meanwhile, the International Court of Justice can only take a case that has been approved by the UN Security Council, over which China has veto power.
"Had any other body, domestic or international, determined or sought to determine these issues, the tribunal would have been unnecessary," Sir Geoffrey said.
The tribunal's final report follows announcement by the US, UK and Canadian government of diplomatic boycotts of the Winter Olympics in China next year.
Mr Johnson said on Wednesday that the UK, like the US and Canada, would not pursue a sporting boycott of the games.