Beijing (CNN) -- Four detained associates of China's recently imprisoned dissident artist Ai Weiwei have been released by the Communist government, Ai's lawyer told CNN Saturday.
The attorney, Liu Xiaoyuan, didn't talk with the four associates, but he asserted that his source about their release is reliable, he told CNN.
"Some of them are still keeping their cell phone off. They've just been released, so they might still feel terrified," Liu said.
Ai was released on bail Wednesday -- apparently with conditions -- after he spent nearly three months in prison on charges of tax evasion, according to the state-run Xinhua news agency.
Ai was not available to comment on the release of the four persons connected with his case, his attorney said.
The release of the four associates occurred Thursday and Friday, Liu said.
Wen Tao, a journalist who was taken away on April 3 -- the same day as Ai -- was released Friday night, Liu said.
Hu Mingfen, Ai's accountant, and Liu Zhenggang, the designer in Ai's studio, were released on Thursday, Liu said.
Liu said he didn't know the charges against these three associates of Ai.
The fourth associate, Zhang Jinsong, Ai's driver, was bailed out by Ai's mother on Thursday, Liu said. Zhang faces a charge of "reselling foreign exchange for profiteering," Liu said.
Beijing police have accused Ai of evading a "huge amount" of taxes, Xinhua reported in May, more than a month after he was detained.
Beijing police told state media that Ai was released on bail because of his good attitude in confessing his alleged crimes and also said he was suffering from a chronic disease. Authorities didn't elaborate.
Ai is an uncompromising, outspoken critic of Chinese policies and is renowned as a conceptual artist, particularly for designing the Bird's Nest stadium for the 2008 Beijing Olympics -- against which Ai later urged a boycott because he said China was using it as propaganda.
Ai has said he is willing to pay the taxes he allegedly evaded, police told Xinhua.
Investigators have also accused Ai's company of intentionally destroying accounting documents.
Observers in Beijing say it may not be coincidental that Ai's release on Wednesday took place on the eve of Premier Wen Jiabao's upcoming visit to Hungary, the United Kingdom and Germany, where Ai enjoys wide support among artists and politicians.
Ai also has accused the Chinese government of trying to silence dissidents.
He was seized April 3 while planning to board a plane to Hong Kong and later accused of economic crimes, a move that prompted international condemnation and added to criticism over China's controversial record on human rights.
Some commentators said they believe the arrests of Ai and his associates may have been launched in response to fears over the unrest that has swept the Middle East.
More than 130 activists have been detained in China since February following the government crackdown, according to Amnesty International.
CNN's Haolan Hong contributed to this report.