FUZHOU,China -Beaten so badly he repeatedly tried to kill himself, when Chen Keyun signed his confession to bombing a Chinese Communist party office he was not even sure what it said.
But with it he was convicted and sent to prison - and only cleared 12 years later after all-consuming lobbying by his family.
His case, and unknown others that remain uncorrected, reflect widespread abuses in China's legal process where police routinely coerce admissions of guilt and courts have a near-perfect conviction rate.
"The whole thing was a joke," said Chen, 61, in his first interview with foreign media, lifting his forearms to show marks left from detention where he said he was hung by shackles, chained into stress positions, force-fed water and made to vomit.
"They used their power to extract a confession from an innocent person - for their own selfish interests," he told AFP, sitting in his lawyer's office in Fuzhou, the capital of the eastern province of Fujian.
"I am very angry."
China's politically controlled courts - the constitution enshrines the leading role of the Communist Party - find 99.9 per cent of defendants guilty, according to the latest US State Department human rights report on the country.
No official Chinese figures are available and the incidence of wrongful decisions is not known, but a series of long-sought reversals have been reported in domestic media this year.
Rights groups say forced confessions are common, and Supreme Court vice president Shen Deyong warned in May that wrongful convictions posed an "unprecedented challenge" for China's judiciary.