Chinese dissident artist Ai Weiwei says police have told him he is stilled barred from leaving the country, despite the expiration of a one-year bail imposed after his release from detention.

The outspoken artist was detained for nearly three months without charge last year. Upon his release, he was charged with tax evasion and told not to leave the capital, Beijing, for a year.

The 55-year-old said Thursday that police now appear to have lifted the domestic travel restrictions, but warned that he should not try to leave the country.

“The police told me that I am still under investigation, therefore I cannot leave China. I asked them when will the restrictions end, and they said they did not know. In my view, this is again another illegal measure.”

The world-renowned artist told reporters he is now under investigation for several other crimes, including spreading pornography on the Internet.

Ai says police have again warned him not to speak to foreign media. He promptly defied the order, just as he did with a similar restriction placed on him when he was released last year.

Ai, an outspoken government critic whose work has been exhibited in the world's leading galleries, was arrested in April last year at the height of a government crackdown that came amid online calls for “Arab Spring-style” protests in China.

He was ordered to pay $2.4 million in back taxes and fines, which his supporters say is part of an effort to silence his activism. He received more than $1 million in donations from supporters who wanted to help with his bond.

On Wednesday, Ai was barred from attending a court hearing of a lawsuit filed by his company, Beijing Fake Cultural Development Ltd., to challenge the fine. The hearing ended without a clear verdict, but Ai told reporters that he is not optimistic about the final outcome.

Ai Weiwei has slammed the government in the past about a number of scandals, including the 2008 Sichuan earthquake that killed scores of students studying in shoddily built schools and deadly fire in a Shanghai high-rise building in 2010.

The accusations of pornography appear to stem from a photo that surfaced on the Internet of the artist posing nude with four women. Ai, who is known for his mocking and satirical art, has rejected allegations that the photo was sexually charged, saying nudity is not always pornography.