Members of China's Uyghur minority joined NGOs on the sidelines of the United Nations Human Rights Council in Geneva to urge UN rights chief Volker Turk to step up pressure on Beijing.

"The UN rights chief should strengthen his efforts to press the Chinese government to implement UN recommendations," Yalkun Uluyol, the China researcher at Human Rights Watch, told diplomats gathered for the event.

Turk's predecessor Michelle Bachelet published a report in August 2022, citing possible "crimes against humanity" in Xinjiang.

The report -- harshly criticised by Beijing -- outlined violations against Uyghurs and other Muslim minorities in Xinjiang, including "credible" allegations of widespread torture and arbitrary detention.

It urged China to promptly "release all individuals arbitrarily deprived of their liberty" and clarify the whereabouts of the missing.

"The recommendations have not been implemented," said Uyghur Rizwangul Nurmuhammad, who has been campaigning for the release of her brother, who was arrested in 2017.

"He was a family breadwinner, a father, a husband, a son, a brother, an ordinary and decent citizen," she said tearfully, holding a picture of her brother.

"Yet he was arrested and sentenced to nine years in prison... with no justification other than his identity as Uyghur," she said.

"This pattern of arbitrary detention carried out systematically by the Chinese authorities, continues today.".

- Abuses 'widespread, systematic' -

Uluyol, also a Uyghur, said he had no contact with his father who was serving 16 years in prison. An uncle was serving a life sentence, and another uncle and cousin were both serving 15-year jail terms.

"All of them were convicted without due process," he said.

A Chinese diplomat in the room took the floor to insist that "claims of arbitrary detention and enforced disappearances are outright lies".

Sophie Richardson, co-head of the Chinese Human Rights Defenders (CHRD) NGO, said "it is fairly clear that these abuses are widespread, systematic", urging Turk to urgently brief the council on the situation.

"We are not short of recommendations on how to address these problems," she said.

"What we are short on is leadership by the High Commissioner and by member states to be courageous ... activists for all of the victims and survivors of Chinese government human rights violations."

Turk's office highlighted to AFP that he had repeatedly raised the issue with Beijing and before the council.

Turk told the council on Monday that "the progress we have sought for the protection of the rights of Uyghurs and other Muslim minorities in Xinjiang... have yet to materialise".

"To be perfectly clear: we stand firmly behind the findings, analysis, conclusions and recommendations of our report," spokeswoman Ravina Shamdasani said in an email.

"It is absolutely crucial that the victims of these serious human rights violations receive effective remedies, and justice."