China returned the passport of the artist Ai Weiwei after holding it for over four years. In April 2011, Ai was detained in the Beijing International Airport as he was about to board for Hong Kong. He was then jailed for 81 days and had his passport confiscated afterwards which placed him under a travel ban. He is known for his vocal protests against the then ruling Communist party.

China claimed that Ai was detained because of tax evasion and several economic crimes, but one prominent speculation was he was detained for provocative artwork he made in 2011, which was offensive to the Communist party. He was also charged with other offenses which included bigamy, pornography, and trade of foreign currency, according to Time.

Despite the restriction to travel, Ai was still able to hold exhibitions and shows in Berlin and New York which he monitored from afar. One of his recent exhibitions was the transformation of the prison in Alcatraz, Time added. Ai designed the memorable "Birds Nest" Olympic stadium that was completed in 2008. He felt remorseful about this project because only China's elite benefitted from this architectural endeavor. 

Tim Marlow, artistic director and co-curator at the Royal Academy of Arts, is delighted with the news about Ai's passport and also announced that Ai will finalize the installation of his exhibit when he goes to London this September. The exhibit will include new artwork and significant past work from 1993 onwards, CNN reported.

Before going to London, he is scheduled to visit Germany for a check-up and to see his son there. It is speculated that the release of Ai's passport may have something to do with the Chinese administration avoiding the issue of his absence when President Xi Jinping visits London next month, according to Seattle Times.