Two exhibitions of works by Chinese artist Ai Weiwei are opening in London this week, just a month after he was detained while at a Beijing airport.
The artist, whose works have been exhibited around the world, has criticized China's Communist Party rulers, and called for political reform. The United States and other countries have called for his release.
Chinese authorities say he is suspected of committing economic crimes.
He has not been heard from since his arrest.
International artists are using exhibits of his work to publicize Ai's detention and to push for his release.
Ai is among the scores of artists, journalists, human rights activists and lawyers arrested in China this year in a crackdown on dissent. Many Asia political analysts say the crackdown appears to be intended to make sure the anti-government uprisings seen this year in the Middle East do not spread to China.
Ai's sculptures of the heads of the 12 animals in the Chinese zodiac are currently on a world tour.