China is asking the United Nations human rights chief to bury a highly anticipated report on human rights violations in Xinjiang, according to a Chinese letter seen by Reuters and confirmed by diplomats from three countries who received it.

United Nations High Commissioner Michelle Bachelet has faced severe criticism from civil society for being too soft on China during a May visit, and has since said she will refrain from seeking a second term for personal reasons.

But before she leaves, at the end of August, she has pledged to publish a report into the northwestern Chinese region of Xinjiang. Rights groups accuse Beijing of abuses against Xinjiang's Uyghur inhabitants, including the mass use of forced labor in internment camps. China has vigorously denied the allegations.