Chinese police released a noted civil rights lawyer Saturday, but he said they warned him to keep quiet about his more than 40 hours in custody.
Beijing police questioned Teng Biao about essays he wrote and other activities he said he did not want to specify. Police then let him go with a warning, he said.
"They asked me not to speak to the media about it," said Teng, speaking by telephone from his Beijing home.
One of a coterie of young activist lawyers, Teng is well known in Chinese and overseas legal and human rights circles. He has defended other activists and worked for constitutional reform.
Teng and prominent political dissident Hu Jia together wrote a stinging essay in September drawing attention to China's human rights lapses in the lead-up to the Olympics.
Hu was detained in December on charges of subverting state power, a vague charge often used against political activists.
In recent weeks, Teng had told visitors that police had confiscated his passport and threatened to detain him. Teng was outside his apartment building in Beijing's northern suburbs Thursday night when police bundled him into a car.
His disappearance set off an immediate outcry Friday from lawyers groups and activists. In a press release, New York-based Human Rights Watch called Teng's detention an "all-time low" for the situation of rights defenders in China. The group called on the International Olympics Committee to intervene.