Conversation so far:
What did Ai Weiwei release?
On 22 June 2011, the Chinese authorities released Ai from jail after almost three months' detention on charges of tax evasion.
What did he do after his release?
After his release, his sister gave some details about his detention condition to the press, explaining that he was subjected to a kind of psychological torture.
What kind of psychological torture was he subjected to?
he was detained in a tiny room with constant light, and two guards were set very close to him at all times, and watched him constantly.
How did the press respond?
Chinese authorities were again investigating Ai and his associates, this time under the charge of spreading pornography.
Was he found guilty?
released after several hours though the exact charges remain unclear.

Question: Was he investigated for anything else?
Self-contained rewrite: Other than for tax evasion and for spreading pornography, was Ai Weiwei investigated for anything else?