Famed Chinese artist Ai Weiwei, who disappeared earlier this month and is believed to be in police custody, is being investigated for allegedly evading his taxes and destroying evidence, a Hong Kong newspaper reported Thursday.
The Beijing-backed Wen Wei Po newspaper quoted unnamed sources as saying Mr. Ai, an outspoken government critic and advocate of social activists, is suspected of evading large amounts of tax, though no exact figure was given, and destroying papers that might have been used as evidence against him.
The paper is often used by the Beijing government to help shape public opinion among Chinese in Hong Kong, which has a vibrant, free media. The report is of a piece with several recent editorials in mainland newspapers attacking Mr. Ai.
It said he also was being investigated for bigamy because he has a young son with a woman other than his wife and is suspected of spreading pornography online.
Before he disappeared, Mr. Ai had been keeping an informal tally of the recent detentions of activists, lawyers and writers on Twitter.
China has stepped up those detentions since February when online calls for protests similar to those in the Middle East and North Africa began to circulate.
Mr. Ai's sister, Gao Ge, called the report "comical" and said the allegations indicated that police have no substantial evidence against her brother.
Ms. Gao said the newspaper report suggested her brother's company was suspected of tax evasion, yet he has no company registered in China.
The pornography allegations were probably linked to his artwork, she said. "That's his art," she said. "I am not going to comment on that."
Mr. Ai and his wife, Lu Qing, were married in the United States but haven't registered the union in China, Ms. Gao said. He has a child with another woman, but the arrangement is open and amicable, she said.
"There is no accuser," she said. "Everyone if fine with the situation as it is."
Ms. Gao said Mr. Ai was being unfairly targeted by police who are themselves breaking the law for not informing Mr. Ai's family of his detention.
The Wen Wei Po said Mr. Ai was cooperating with authorities after initially refusing to do so when he was first taken into custody April 3.