Chinese artist Ai Weiwei under house arrest

Acclaimed Chinese artist and activist Ai Weiwei says he's under house arrest, which prevents him from attending the razing of his studio in Shanghai by Chinese authorities.

The Beijing-based Ai invited fans and supporters, via Twitter,to a "River Crab Fest" at his newly built Shanghai studio on Sunday.

The fete was to draw attention to the government's destruction of the studio in the city's financial area.

"I'm under house arrest [in Beijing] to prevent me from going to Shanghai," the 53-year-old artist and designer said late on Friday. "You can never really argue with this government.

'They've told me I would be held until midnight Sunday.' Ai Weiwei, artist

"They've told me I would be held until midnight Sunday and I would be prevented from leaving before then."

Ai was invited by the head of Shanghai's business district to create a studio space on a plot of land. He spent two years designing and building the studio, only to be hit with an edict in July stating the building was an illegal structure because he hadn't secured the proper permits.

"They're very contradictory," Ai said, referring to the local officials who declared his studio illegal. "They asked that I donate the building to the government for a museum, but how could I do it if it's an illegal structure?"

Other artists building on the same site have not been affected by the destroy order.

Many of his guests, who include musicians, artists and journalists, have said they plan to go to the demolition even though the party has been cancelled.

Ai has been a controversial figure for the Chinese government. The son of one of China's most famous poets, Ai Qing,he has carved a name for himself internationally with his art installations.

Most recently, he made headlines with his Sunflower Seeds exhibitat London's Tate Modern, filling one of its halls with 100 million porcelain seeds.

He famously quit the consortium working on the Bird's Nest stadium built for the 2008 Olympics in Beijing, charging that China was offering a whitewashed image.

Ai continues to investigate the deaths of more than 5,000 schoolchildren in the Sichuan earthquake of May 2008 and suffered a beating he claimsit came from police officials while in Sichuan province in August 2009, just before he was to testify in a court case involving another activist researching the earthquake.