Chinese artist Ai Weiwei , endured intense psychological pressure during 81 days in secretive detention. In the first broad account of Ai's treatment in detention since he was released in June, the source, who declined to be identified fearing retribution, said the 54-year-old artist was interrogated more than 50 times by police, while he was held in two secret locations.
The questioning focused on his purported role in the planned Arab-inspired "Jasmine Revolution" protests in China in February and his writings that could constitute subversion, said the source.
That account runs counter to the Chinese government's repeated statements that Ai's detention was based on alleged economic crimes.
"What you're doing is illegal," Ai told police officers at one point, according to the source. "They said: 'Do you know before Liu Shaoqi died, he was holding the constitution...Talk about illegality, there's no difference between the country that we are in now and the time of the Cultural Revolution."
Liu, a former president, was purged and died in prison during the 1966-76 Cultural Revolution when paramount leader Mao Zedong turned against his comrades in the name of radical upheaval.
In the second location, where Ai was held for 67 days, the artist famed for his work on the "Bird's Nest" Olympic Stadium in Beijing, was watched over by two police officers for 24 hours a day, with their faces often inches from his, watching his every movement even while his slept.
Ai had to ask the police officers for permission to drink water and use the toilet. He was not allowed to speak and was watched over by the officers even while he slept. They demanded that he put his hands on top of the blanket, the source said.
"It was immense psychological pressure," the source said.
Under the conditions of Ai's release, he is not allowed to be interviewed by journalists, meet with foreigners, use the Internet and interact with human rights advocates for a year from his release, the source said.
Despite this, the burly artist, with flecks of grey in his distinctive beard, has spoken out on his Twitter account for detained dissidents and his associates who had disappeared during the time that he did but have since been released.
During his detention, Ai was fed well and allowed long walks, the source said.
Ai has long been an outspoken government critic, and for a long time, many believed Ai had been somewhat protected by his fame and by being the son of a famed Communist poet, Ai Qing.
But when Ai was taken from the airport by plainclothes officers on April 3, they covered his head with a black hood, put him in a car and drove him to a secluded location, the source said.
Ai was told that he was being put under "residential surveillance." He asked whether he could have access to a lawyer or whether his family knew of his whereabouts, and police officers told him that could take up to six months.
While he was held, the source said, Ai was asked whether he knew who the organisers of the "Jasmine" protests were. Ai denied all knowledge, the source said.
Police officers discussed the contents of his blog and Twitter account, "line by line," the source said.
He was told he could face 10 years in prison for "inciting subversion to state power" -- a broad charge that China often uses to punish dissidents.
On the day he was released, police officers told him he "could still be sentenced to 10 years," the source said, adding that Ai had to sign a contract stating that he would agree to the terms of his release before he could be released.
Ai's detention ignited an outcry from many Western governments about China's tightening grip on dissent that started in February, when dozens of rights activists and dissidents were detained and arrested.
The artist was the most internationally well-known of those detained, and his family has repeatedly said he was targeted by authorities for his outspoken criticism of censorship and Communist Party controls.
During the nearly three months of detention, his family and friends said his whereabouts were unknown. Ai met his wife Lu Qing once at a time when rumors circulated that he was being tortured.
When Ai was released on bail in late June, the Chinese government said he remained under investigation for suspicion of economic crimes, including tax evasion. Ai told Reuters earlier that he has not received a formal notice from the authorities to explain the charge of "suspected economic crimes."
Police officers told Ai "you criticised the government, so we are going to let all society know that you're an obscene person, you evaded taxes, you have two wives, we want to shame you. We'll not use politics to deal with you," the source said.
The source said Ai told them "no one is going to believe you," but officers told him "everyone will believe us, tax evasion is a very serious crime in many countries."
Despite the intimidation, Ai is unlikely to leave the country for good, the source said. He had confirmed earlier to Reuters that he had accepted a visiting teaching post at the Berlin University of the Arts and that he would like to go to Germany, if given permission by the authorities.
Ai will not abandon his once prominent role as a free speech advocate, the source said. On Tuesday, Ai tweeted that if people do not speak out for dissidents Wang Lihong and Ran Yunfei, they do "not stand for fairness and justice...and have no self-respect."
On Monday, he tweeted about the conditions of four associates who had been detained at the same time as Ai, saying "they innocently suffered immense mental devastation and physical torment."