'Big relief' as Chinese authorities release associates of artist Ai Weiwei

The four included journalist Wen Tao, who was detained along with Ai in early April when the two were at Beijing airport heading to Hong Kong. Ai was released last week.

Liu Yanping, a volunteer worker involved in Ai's campaigning on rights issues, said: "All of the people connected to the case have been released. That's a big relief. But I do think the Ai Weiwei studio's work will remain suspended for now."

She added that she was referring to Ai's politically charged activism, not to his artistic work.

The detention of Ai and his associates marked the start of the contentious case which the Chinese government said was about suspected tax evasion, while Ai's family and supporters said it was part of a political drive to silence him and other critics of the ruling Communist Party's censorship and controls.

Ai's accountant, Hu Mingfen, a designer in Ai's studio, Liu Zhenggang, and the artist's driver, Zhang Jinsong, who all went missing in April, were also freed last Thursday or Friday, according to Liu, the volunteer, as well as Liu Xiaoyan, a lawyer close to Ai Weiwei.

The 54-year-old artist was freed on bail last Wednesday, a day before Chinese Premier Wen Jiabao left for Europe, where he will visit Britain and Germany, two nations that decried Ai's detention.

The release of Ai and other activists has marked a stepdown of sorts by Chinese authorities, who have rarely flinched in prosecuting critics of party rule. But the tax charges and release conditions that hover over Ai and his released friends are likely to ensure they stay publicly silent for now.

Other Chinese dissidents and human rights lawyers detained and then released in recent months have also said they must stay quiet in return for their release. Zhang, the driver, was also released on bail, said Liu Xiaoyan, the lawyer. But he and Liu Yanping, the volunteer, were unsure whether bail terms applied to the other three freed.

"My understanding is that Wen Tao is not allowed to speak out about what happened," said Liu Yanping. "I think the others will be in the same situation."

Officials have told Ai that he cannot speak out, tweet or travel without their permission for a year.

Before his detention, Ai constantly blogged and Twittered on sensitive subjects including the deaths of students in shoddily built schools that collapsed during the 2008 Sichuan earthquake and children killed or sickened by tainted infant formula.

The Foreign Ministry said the conditions of Ai's parole require him to report to police when asked and bar him from leaving Beijing without permission for one year.

Analysts say Ai's release is far from a sign of a U-turn by the ruling Communist Party. Authorities have muzzled dissent with the secretive detentions of more than 130 lawyers and activists since February, amid fears that uprisings across the Arab world could trigger unrest.