Washington, Dec 29 (IANS): A Uyghur Muslim preacher, serving a five-year sentence in China's far-western Xinjiang region for making a religious pilgrimage abroad, died of liver cancer in prison in February, according to a police officer who works in the district where the preacher resided, RFA reported.

Omar Huseyin, 55, was the former hatip, or preacher, at the Qarayulghun Mosque in Korla, known as Ku'erle in Chinese and the second-largest city in Xinjiang. Authorities apprehended him in September 2017 amid a widespread crackdown on Islamic clergy and other prominent Uyghurs, for travelling to the holy city Mecca in 2015, RFA reported.

Authorities also detained Huseyin's three brothers in 2017, one of whom was serving a 12-year sentence for participating in religious activities and died in prison.

Huseyin was healthy before authorities took him away for "re-education" in one of hundreds of facilities across Xinjiang where authorities detained an estimated 1.8 million Uyghurs and other Muslims purportedly to prevent religious extremism and terrorism, RFA reported.

Mahmut Moydun, a Uyghur inmate who escaped from another prison in Korla and was in hiding, said that conditions at detention centres had been deteriorating because more inmates, including the preacher, had died in the last two years.

A Korla resident, who declined to be named for safety reasons said the health of inmates incarcerated in city prisons had deteriorated due to low quality food, the intensity of prison labor, long political study sessions, and endless interrogations.

Huseyin was taken away for "re-education" in 2017 at a time when authorities were transforming internment camp centers in Korla into prisons, he said.

A district policeman later confirmed that Huseyin was serving a sentence in the district prison and that he died on February 2.

"He was healthy and was not sick at all before," the officer said. "We learned that he died of late-stage liver cancer in the (prison) hospital. He died while being treated without being released."

"At the time, the (Chinese Communist) Party and the government organised delegations to make the pilgrimage to Mecca, and he went there as a delegation member," said the police officer, referring to a time before the 2017 crackdown when authorities encouraged Uyghurs to apply for passports and travel abroad, RFA reported.

After authorities arrested Huseyin for making a pilgrimage to Mecca, he was put on trial and sentenced to five years in jail, he said.