Dui Hua had a list of a handful of other unaccounted-for prisoners, but could verify only one serving prisoner.
"Based on what happened to others, dozens who were given life in prison or a suspended death sentence, they would be out. But we do not know," Kamm said.
A cellmate who spent time with Miao in Beijing's No 1 prison, where he was initially confined, said his sentence had been extended because he refused to cooperate with the prison authorities. "Miao was very opinionated about the Communist Party and he refused to do the work we were set in prison," he said.
At the time the inmates manned a badminton racket production line inside the block. Each day, they would rise at 6am and work until 10pm, breaking to eat watery cabbage soup ladled from an old oil barrel that had its top sliced off.
"Everyone had their sentence cut for good behaviour, one way or another, but Miao never got anything," said the cellmate.
"His sentence was extended not long after he was thrown in because he refused to do the labour. It got him beaten up over and over. He was always thrown into solitary confinement, once for two months, because he had rebelled against the guards."
About 182cm tall and rake thin, Miao seldom spoke, but stood out among the prisoners. "He was so skinny and he developed hepatitis and often went to the clinic," he said.
"He never slept at night and sat on his bed all day while everyone else worked. He refused to consider himself a prisoner and he would spend days reading the newspapers, analysing every article."
Five years after his imprisonment, his family had stopped visiting. "His father used to come frequently, always crying, and he would buy things for him," said the cellmate. "But I think he did not want his family to have to look after him, he wanted to be responsible for himself. After his father stopped visiting, he had no money. He only had 6 yuan ($1.12) a month and would spend 2 yuan on soap, 2 yuan on toilet paper and 2 yuan on washing powder. The others gave him food sometimes."
Another ex-prisoner said the authorities had stopped Miao's family from visiting because he would not confess to his crimes.
Miao is now in Yanqing prison, a facility for inmates with medical conditions. He is scheduled for release in 2018, but may have nowhere to go. "He suffers from severe mental illness," said Kamm.