China's most famous modern artist, Ai Weiwei, says he's been placed under house arrest in Beijing.
Mr Ai, who is also known for his political activism, says the authorities want to prevent him holding a party to mark the forced demolition of his new Shanghai studio.
The artist was initially invited to build the space, but $US1.1m studio has now been declared illegal and will shortly be demolished.
Mr Ai helped create Beijing's Olympic Bird's Nest stadium and his latest installation made up of millions of tiny replica sunflower seeds is showing at London's Tate Modern.
Born in 1957 in Beijing, the artist has played a key role in contemporary Chinese art over the last two decades, and has been highly vocal about human rights issues in the country, the BBC reports.
On Friday, he said that men he suspected were plain-clothes police officers told him he would not be allowed to travel to Shanghai.
A van without numberplates with more than 10 men inside was blocking the exit from his home at an artists' colony in Beijing, he added.
