Chinese authorities detained well-known artist and government critic Ai Weiwei to keep him and others from testifying at the trial of an activist who investigated the collapse of schools in last year's earthquake.
Ai Weiwei was detained at a hotel in the city of Chengdu. Police released him later in the day and he boarded a plane to Beijing. Speaking from the Chengdu airport, he says about 30 police came to his room claiming they were doing a routine check.
"They just kicked on the door and yell and said, 'Police, everybody out!' It was like, how do you say, a Hollywood movie," he said. "I said 'how do I know you are police?' He said 'let me show you', and just kicked the door open, the lock [is] all broken."
The co-designer of the Bird's Nest - the national stadium that was home to the 2008 Beijing Olympics - says when he pressed the police to state their purpose, he was punched in the face. Some of the 10 volunteers with him were taken into custody, while he and others were detained in the hotel room for 11 hours.
Ai was in Chengdu to testify at the trial of Tan Zuoren. He faces subversion charges, most likely linked to his investigation of schoolchildren's deaths in last year's Sichuan earthquake. China frequently uses the charge of subversion to imprison dissidents.
The artist was to testify about his own investigation into problems with school construction in the earthquake area. Ai organized volunteers to collect names of child quake victims. His volunteers went to Sichuan to film interviews with families who lost children.
About 5,300 children died in the earthquake because their school buildings collapsed. Parents of many of the victims complain that the schools were poorly built because of corruption or neglect.
Tan's lawyers asked to call Ai and two other witnesses, but were refused. They also asked to show video filmed by Ai's volunteers, the court rejected that request, too.
The trial ended Wednesday afternoon, and Ai was released after that. It is not known when the court will issue a verdict.
Ai says this was a learning experience for him about the legal system in China.
"It is completely a fake trial, it is all set up," he said. "They submitted some of my evidence to the court, but it does not matter. No matter how [much] evidence you have they will never change. It is impossible."
Some of Ai's volunteers are still in custody. Ai says he has a right to sue the police for assaulting him, but he feels it is pointless.
"If you sue them you still have to apply in their court, and you can never succeed. That is why many people give up on the so-called lawful channels," he said.
Amnesty International and Human Rights Watch have urged China to drop charges against Tan and another earthquake activist, Huang Qi, calling the prosecutions politically motivated. Huang was tried last week for illegally possessing state secrets, but as yet, no verdict has been issued.
During the past several weeks, the government has increasingly clamped down on activists and groups that question its actions. Political analysts say it appears the Communist Party wants to shut off dissent before the 60th anniversary of the creation of the People's Republic of China, in October.