China has sentenced a high-profile Uyghur academic to life in prison on charges of "endangering state security", a US-based rights group said, citing a Chinese government source.
Rights advocates have accused China of launching a mass internment campaign targeting Uyghurs, along with abuses such as forced sterilisation and cultural repression, termed "genocide" by some government bodies, including the US State Department.
China vigorously denies such accusations.
In a statement, the Dui Hua Foundation said Rahile Dawut, 57, lost her appeal against her original conviction from December 2018.
"This is believed to be the first time that a reliable source in the Chinese government has confirmed the sentence of life imprisonment," it added in last week's statement.
China's state council, or cabinet, did not immediately respond to a fascimile message requesting comment.
Chinese courts have a conviction rate of 99.9% and acquittals are rare in the opaque judicial system.
Prior to her detention, Dawut had been a professor at Xinjiang University College of Humanities, as well as a leading cultural anthropologist and ethnographer of Uyghur folklore.
She had been detained since December 2017 in the northwestern region of Xinjiang, where Beijing has been accused of rights abuses against the mainly Muslim Uyghur ethnic minority, which it denies.
"The sentencing ... is a cruel tragedy, a great loss for the Uyghur people, and for all who treasure academic freedom," said John Kamm, executive director of the Dui Hua Foundation.
"I call for her immediate release and safe return to her family."
Dawut joins a list of more than 300 Uyghur intellectuals who have been detained, arrested or imprisoned by Chinese authorities since 2016, the group added.
She worked with many prominent Western institutions, such as the universities of Harvard and Cambridge, which have called for her release.
Some Xinjiang experts say the alleged mass internment of Uighurs peaked in 2018, but that abuses have continued with forced labour becoming more prominent.
"I worry about my mother every single day," said Dawut's daughter, Akeda Pulati, who is based in Seattle.
"The thought of my innocent mother having to spend her life in prison brings unbearable pain," she added, in a statement released by Dui Hua Foundation.
"China, show your mercy and release my innocent mother."