‘It’s absolutely not true’

China's claim that "most" inmates have been released from re-education camps in its Xinjiang region has been met with anger and scepticism by the Uighur diaspora which has launched a social media campaign challenging Beijing to prove it.

Rights groups and experts say more than one million mostly Muslim ethnic minorities have been rounded up in internment camps in the tightly-controlled northwest region, home to China's Uighur population.

But on Tuesday, Xinjiang officials told reporters that "most" people held in the camps had already returned home -- though they did not share any figures.

"It's absolutely not true," said Guly Mahsut, a Uighur based in Canada.

"One of my cousins and one of my tour guide friends, and my friend's husband, they are still in the camps," the 37-year-old told AFP.

Mahsut and other overseas Uighurs have responded to China's claim with the hashtag "#Provethe90%", featuring stories and photos of missing friends and family who they have been unable to contact in Xinjiang.

The hashtag is a reference to remarks made by Xinjiang chairman Shohrat Zakir, who told reporters "more than 90 percent" of those who "return to society...have work that they like and find suitable."

"China does not need to say they released most if they really did so," said Arfat Erkin, a Uighur student in the United States who tweeted about his father using the "#Provethe90%" hashtag.

Asked about the scepticism, foreign ministry spokeswoman Hua Chunying said Wednesday that she was "not aware of the specific number" of people who have left the centres.