Chinese dissident artist Ai Weiwei said Thursday he was still barred from leaving the country despite the expiry of a one-year bail condition imposed after his release from detention last June.

The outspoken 55-year-old, whose works have been exhibited in scores of countries, spent 81 days in custody last year as police rounded up dissidents amid online calls for Arab Spring-style protests in China.

On his release on June 22, 2011, authorities accused him of tax evasion, took away his passport barred him from leaving Beijing for a year -- a restriction that has prevented him from attending his own exhibitions overseas.

On Thursday, Ai told AFP he had received an official order announcing the end of his bail term, but that he was still barred from leaving the country because he was under investigation for alleged crimes including putting pornography on the Internet.

"This morning, I went to the police station... My one-year probation is finished, but they said they will still limit my rights to travel," he said. "The order says I cannot travel outside of China."

Ai said he was unsure whether he was now able to leave the capital, but added the order did not specify that he was prohibited from travelling within China.

"They said I'm still under investigation for my other crimes. So I said,'you have to make a case, you can't just say that'.

"I asked what crimes, and they said crimes such as putting pornography on the Internet."

Ai said last November that he had been accused of pornography when he was detained, apparently in relation to old pictures posted online of him posing with naked women.

He said he had ridiculed the charges -- telling police "nudity is not pornography" -- until police called in his assistant for questioning on the issue.

On Thursday, he said his wife's movements had also been restricted over the past year, and that police had been unable to tell him whether she was free to travel.

Ai's detention last year sparked an international outcry, with the United States and the European Union leading calls for his release.

The official Xinhua news agency said after Ai's release that he had "confessed" to tax evasion via the Beijing Fake Cultural Development Ltd., a company he set up but which is legally registered in his wife's name.

He has denied this, denouncing the charges as politically motivated and designed to "crush" his activism.

Ai has previously riled the ruling Communist Party with high-profile investigations into the collapse of schools in the 2008 Sichuan earthquake and into a 2010 fire at a Shanghai high-rise that killed dozens of people.

On Wednesday, lawyers for Fake went to court to try and challenge the tax evasion charges and a multi-million-dollar penalty brought against Fake -- a hearing blanketed in heavy security that Ai himself was not allowed to attend.

In an indication of how sensitive the case is, other activists reported being restricted or harassed by authorities on Wednesday.

Liu Xiaoyuan, a legal adviser to Ai Weiwei, said Thursday authorities had forced him to leave Beijing and return to his native Jiangxi province, while veteran dissident Hu Jia said he was beaten by state security forces Wednesday.

The hearing lasted more than nine hours, and lawyers said at the end that the court now had until early August to give a ruling.

Before his detention, the burly artist travelled extensively, holding exhibitions of his installations, sculptures and photographs in many countries around the world.

The value of his work has shot up since his detention thrust him into the global spotlight, and in October Britain's influential Art Review magazine named him the most powerful figure in the art world.

His latest high-profile piece of work is a pavilion for this year's London Olympics that he helped build with Swiss firm Herzog & de Meuron, with which he had previously collaborated to create Beijing's Bird's Nest Stadium.

Ai contributed to designing the pavilion for the Serpentine Gallery in London's Kensington Gardens park, reportedly using Skype to coordinate with the company as he was unable to leave Beijing.