Chinese state media has released a video it said proves Uighur poet and musician Abdurehim Heyit is alive, after Turkey cited reports of his death in custody in a strongly worded condemnation of "human rights violations" in Xinjiang.

In the 26-second video posted online by China Radio International's Turkish language service late on Sunday, a man dressed in a grey sweater identifies himself as Heyit before declaring himself to be in "good health".

"Today is February 10, 2019," he said. "I'm in the process of being investigated for allegedly violating the national laws. I'm now in good health and have never been abused."

Reuters was unable to independently confirm the authenticity of the video.

On Saturday, in a rare move from a majority-Muslim power, the Turkish Foreign Ministry called on China to close its internment camps for Muslims, saying the camps said to hold a million ethnic Uighurs are a "great shame for humanity".

That statement had come in response to a question about recent reports that Heyit, a well-known poet and musician, had died while in Chinese detention, having been "sentenced to eight years in prison for one of his songs".

"This tragedy has further reinforced the reaction of the Turkish public opinion towards serious human rights violations committed in the Xinjiang region," ministry spokesman Hami Aksoy said on Sunday.

China's embassy in Ankara said Aksoy's accusations were false and urged the Turkish government to retract them.

Uighur diaspora activists said Heyit's body language and unnatural speech patterns in the video suggested his testimony may have been coerced and that even digital alteration could not be ruled out.

International rights groups say China routinely coerces detainees into making videotaped confessions which are then broadcast through state media to serve the government's propaganda objectives.

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