The novelist Murong Xuecun was questioned and later released by the police after he admitted he was involved in a private gathering to commemorate the 25th anniversary of the suppression of the pro-democracy movement in Tiananmen Square.
Several rights activists were detained after attending the event in May, including the civil rights lawyer Pu Zhiqiang.
Murong Xuecun, whose real name is Hao Qun, was unable to go to the gathering as he was attending an event at the University of Sydney in Australia, but he released a public statement on Saturday saying one of his essays on the crackdown was submitted to the meeting and he wanted to show his support for those detained.
"I oppose their detention. I have done the same thing as them and should not enjoy any sort of exemption," he said in the statement, which was circulated on social media over the weekend.
"I will stay at home for the next 24 hours waiting for arrest, but please call me to make an appointment if you fail to make it in the next 24 hours," he said.
Hao also wrote in a column in The New York Times in May about the speech he sent to the gathering.
"Reciting such an essay at a private gathering can violate China's laws," he said. "By the government's logic, I, too, have committed the crime of 'picking quarrels and provoking trouble'. I am going to turn myself in."
Beijing police called Hao on Tuesday and asked him to come in for "a cup of tea", a euphemism widely used on the mainland for a summons, Hao said in an interview with the German broadcaster Deutsche Welle before heading to the station at dusk.
"The police called me about an hour ago. I asked them to wait as we've already scheduled this interview," he said.
He added he was prepared for a jail sentence.
"No one likes or wants to be imprisoned, but I want to do the right thing," he said.
"If a jail term is the price I have to pay, then so be it."
Human rights lawyers and activists, including Guo Yushan and Zhang Qingfang, stayed outside the police station and live blogged the progress of the case to support Hao.
He was released after midnight and joined his supporters for a late-night snack, Guo posted on his social media account.
An attempt to contact Hao yesterday by the Post yesterday was unsuccessful.
Pu, who also was detained ahead of the 25th anniversary of the Tiananmen Square crackdown, was formally arrested last month for "creating disturbances" and "illegally obtaining personal information".
Police said they were also investigating other alleged offences.