A dissident who had been one of China’s longest-serving political prisoners until his release last week was tortured while in detention and has been threatened since he was let out, he said in a statement released yesterday.

The ethnic Mongol activist, Hada, has spent much of the last two decades behind bars, including the last four years in an extra-judicial “black jail”, but was released last week.

The government fears ethnic unrest in border areas and keeps a tight rein on Inner Mongolia, just as it does on Tibet and Xinjiang in the west, even though the region is supposed to have a large measure of autonomy.

“During these 19 years, in an effort to force me to abandon my beliefs, I was cruelly mistreated and subjected to various forms of tortures and ploys,” Hada said in a Mongol-language video statement, which was released by the New York-based Southern Mongolian Human Rights Information Center.

“In particular, my wife and son have been subjected to false accusations, enormous persecution and suffering. I myself have been disabled as a result of torture and brutality,” Hada said, according to a translation provided by the group.

Calls to the Inner Mongolia government seeking comment went unanswered. The use of torture is banned in China, but rights groups say it remains widespread.

Hada’s wife, Xinna, and their son, Uiles, have been in and out of detention over the past few years. Reuters was unable to reach any of them by telephone.

Many Mongols in China go by just one name.

Hada was tried in 1996 and jailed for 15 years for separatism and spying and also supporting the Southern Mongolian Democratic Alliance, which sought improved rights.

Hada called the charges against him “trumped-up”, adding he was still effectively being treated as a prisoner, banned from talking to media or anyone other than his family.

“My next step is to arrange my life and study, to continue to fight against the oppression of the Mongolian nationality.”